Common Outlook OST File Errors and Solutions

Read time: 15 minutes

As an email client, Outlook serves a domain of customers, ranging from individuals to large enterprises. With robust and dependable features, Outlook is proving to be the first choice for handling or managing formal email communications within organisations.

However, this reliable email client is also susceptible to various issues and errors. The accumulation of different unique features in Outlook increases the application complexity, which is directly proportional to development errors.

We have thoroughly analyzed various forums & sites. From our founding, we have compiled the most common Outlook errors & issues causing low productivity and data loss among users & businesses.

Moving further, in this blog, you will become familiar with the most common OST file errors in Outlook. However, before we begin our list of errors, let us first understand the probable cause of the problem.

Reasons Why Users Encounter Common OST File Errors

Outlook has a complex application structure and can show several common OST file errors due to numerous reasons. The most common reasons are:

• Corrupt/damaged OST file.
• Connectivity issue in Outlook.
• Synchronisation issue between Outlook and Exchange Server.
• Storage related errors.
• An issue with the email server.

Note: If you are experiencing any issues in Outlook, you must immediately make a backup of your mailbox to prevent data loss.

Common OST File Errors Due to Corrupt/Damaged File

Corruption in the Outlook OST file is not very uncommon. Reasons for OST file corruption include malware attacks, improper shutdown of Outlook, oversized OST file, etc. Having any one of these situations can easily damage the Outlook data file and create common OST file errors.

The following issues/errors are reported by users when dealing with a damaged OST file and corrupted Outlook profile.

1. Errors Have Been Detected in the File xxx.ost

While accessing Outlook, this is among the common OST file errors you will encounter. It occurs when your Outlook OST files are corrupted/damaged, preventing you from accessing Outlook.

In case you don’t see the specific error while operating Outlook, then you can also keep an eye out for certain symptoms that indicate the presence of issues within the OST file. Witnessing the following symptoms creates the possibility of OST file corruption:

• Outlook application frequently crash and lag.
• Large OST file size.
• Improper OST updates.
• Crucial mailbox data missing from OST files.
• OST file is taking too long to load.
• Mailbox doesn’t have recent emails, calendars, or contacts.

Solution

You can solve the error “Errors have been detected in the file xxx.ost” by trying different methods such as:

• Creating a new OST file for your Exchange account.
• Utilizing the in-built Microsoft Inbox Repair tool.
• Try to sign out and log in again. Utilizing the in-built Microsoft Inbox Repair tool and more.

2. ‘Your Mailbox Has Been Temporarily Moved to Microsoft Exchange Server’ Error

If your OST file is damaged, then Outlook will find it difficult to load and connect to the offline Outlook data file, leading to various problems. With the Outlook error “Your mailbox has been temporarily moved to Microsoft Exchange Server”, you will face a corrupted Outlook profile or a damaged OST file.

The Use Temporary Mailbox option given in the above dialogue box may look like a good fix if you are in a hurry, but we advise against it as this may cause permanent data loss.

Solution

To fix the error “Your mailbox has been temporarily moved to Microsoft Exchange Server” try the following troubleshoots:

• Enable Cached Exchange Mode
• Create a new Outlook profile
• Enable ModAuth in Outlook
• Disable faulty add-ins

3. Error 0x80190194

The Error 0x80190194 is also known as the Outlook Offline Address Book (OAB) error. This error is seen when users try to download the offline address book manually. A common reason leading to such an error is corruption in Outlook data file.

Apart from corruption, factors like virus attacks, improper OAB URLs, invalid SSL certificate, and corrupted Outlook profile can also introduce this error.

Solution

To remove the Outlook 0x80190194 error user can try the following troubleshoots:

• Create a new Outlook profile.
• Rename Outlook folder
• Clearing the contents of the OAB could also aid in this situation.

4. “Cannot Open Particular Outlook Items When Offline” Error

The OST file serves as the offline replica of the Exchange Server. All the files and folders stored on the server are available locally with the OST file. However, when accessing these local mailbox items, Outlook sometimes throws an error “Cannot open particular Outlook items when offline.”

A common reason behind the error is a corrupted Outlook profile. Also, having a misconfigured or damaged Outlook profile creates several issues when accessing Outlook.

Solution

To resolve cannot open particular Outlook items when offline error, you can try the following proven methods:

• Recreate OST file
• Use Inbox Repair tool to fix OST file.
• Make a new Outlook profile.

Common OST File Errors Due to Poor Network Connectivity

Sometimes, the reason for having trouble in emailing with Outlook is due to a slow or misconfigured network connection. To send/receive emails, you need a proper internet connection that provides enough bandwidth for seamless email management.

The common Outlook errors that you may encounter due to poor internet connectivity are listed below:

1. “Cannot Expand the Folder” Error

While trying to expand a shared folder or public folder in Outlook, you may encounter an error, “Cannot expand the folder”. This error could arise due to several factors, but mainly due to interference in Outlook connectivity to the server.

The presence of such issues is annoying and hinders the user’s productivity, resulting in low work output. Therefore, you must implement an immediate solution in such a case.

Solution

To fix the error “Cannot expand the folder”, you can try a bunch of different approaches, such as: you can try a bunch of different approaches such:

• Make the Folder visible again.
• Try to disable Outlook add-ins.
• Creating a new Outlook profile.
• Using Microsoft Support and Recovery Assistant (SaRA).
• Repair Outlook and more.

2. “Outlook Disconnected from Exchange Server” Error

When you launch Outlook, it immediately tries to connect to the Exchange Server and synchronise the files and folders. However, sometimes, a network issue may disrupt the connectivity between Outlook and Exchange Servers. Such network interference can lead to the error “Outlook disconnected from the server”.

Apart from connectivity issues, other factors can also influence Outlook to throw this error, such as:

• Exchange Server facing downtime.
• Damaged Outlook data files.
• Certificate issues

Solution

To fix the “Outlook disconnected from the server” issue, you must execute the following troubleshoots immediately.

• Check network configuration and ensure a stable internet.
• Toggle the Outlook Work Offline mode to switch to online mode.
• Run Outlook in safe mode.
• Create and use a new Outlook profile.
• Verify and install the necessary certificates.

3. “Outlook Cannot Log On. Verify You Are Connected to the Network” Error

Users have reported and raised concerns about this error, which doesn’t let them log in to Outlook. The inability to successfully log in to Outlook halts email communication within the enterprise. Such situations confuse employees. Users have reported poor connectivity as the main reason for this error, among other factors like damaged Outlook profiles or data files.

Solution

To fix “Outlook cannot log on” error, you can try below methods:

• Using Microsoft Support and Recovery Assistant.
• Running the resetnavpane command.
• Recreate the OST file.

4. “Not implemented” Error During Send/Receive

When the Outlook user clicks Send/Receive or tries to send an email, it can lead to such an error. This issue indicates that a core Outlook function (Send/Receive operation) has failed. The common reasons for this error are:

• Faulty or corrupt add-ins.
• Broken or incompatible Outlook profile.
• Outdated or conflicting Outlook updates.
• Corrupt SRS (Send/Receive Settings) file.

Solution

To fix the “Not implemented error”, you can try the following expert solutions:

• Repair the Office installation.
• Disable add-ins.
• Create a new Outlook profile.
• Delete and rebuild the SRS file.
• Check for Outlook updates.

Common OST File Errors Due to Synchronisation Issues

Another important element for a smooth email experience is having a proper and timely synchronisation between Outlook & Exchange Server. The contents of the OST file need to be updated periodically to ensure the availability of the latest emails and other mailbox items offline. You can read below for the various common OST file errors due to improper Outlook synchronisation with the Exchange Server.

1. There are More Items in This Folder on the Server.” Error

As we have discussed above, the OST file is a replica of your files & folders on the Exchange Server. Any synchronisation issue can evolve into a critical situation, requiring immediate solutions. This error indicates that there are more than 1000 items in a folder, and the server fails to load all of them at once. This could prevent the availability of the latest files offline in the OST file.

Conditions like these would have a negative impact on a user’s performance, which would ultimately lead to diminished productivity. Apart from the lack of correct synchronisation, other factors that could lead to the above error are:

• Weak internet connectivity
• Damaged Outlook profile
• Outlook Cached Exchange Mode is turned off.

Solution

To fix “There are more items in this folder on the server” issue. You can try the below-mentioned methods to solve it:

• Clearing Outlook cache could help load all the items efficiently.
• Modify the Outlook registry setting.
• Rebuilding the OST file.

2. Outlook “0X80072f06” Error

This error is related to the Outlook Offline Address Book (OAB) as we discussed above in the OST corruption section. However, this time, the issue is being raised due to a desynchronization between the Outlook OAB and Exchange Global Address List (GAL).

A seamless synchronisation between OAB & GAL is crucial to manage and access the Outlook emails smoothly in offline mode. Other elements that could also aid in the development of the Outlook “0X80072f06” error:

• Irregular updates to the .oab files.
• Problem regarding security certificates of Exchange.
• Damaged Windows system files.
• Incorrect setup of Outlook application.

Solution

To fix the Outlook “0X80072f06” error and enable a smooth synchronization of OAB and GAL, you can perform the following procedures:

• Update or delete the existing OAB file.
• Perform a system restore to restate the damaged system files.
• Reset the Outlook profile.
• Verify the Exchange security certificates.

3. IMAP Synchronisation Issues in Outlook 2013/Office 365

Regular updates are essential for smooth functioning of any application. Microsoft releases timely updates for Windows to add new features or enhance security. However, it has been observed that certain updates, such as KB2837618 or KB2837643, turn out to be incompatible with Outlook, resulting in synchronization issues between IMAP and Outlook.

Users have reported encountering the problem mostly in the Outlook version 2013 & Office 365. We have discussed in the above errors how critical the situation can be in case of a lack of synchronisation.

Solution

To resolve the IMAP synchronization issues in Outlook and achieve perfect synchronism use the below-mentioned techniques.

• Uninstall updates from the Control Panel.
• Modify the path of the root folder for IMAP account.
• Setup a new Outlook profile.
• Tweak Outlook Folder settings.

4. “The Deleted Items Folder is Unavailable” Error

When users delete some items from Outlook, those files don’t disappear immediately. The deleted files are moved to a folder named Deleted Items folder. However, sometimes the user is unable to find the Deleted Items folder in Outlook in case they want to restore a deleted item.

The inability to find and restore an accidentally deleted data item could put the user in a confused state. The disappearance of the Deleted Items folder can be triggered due to various reasons, such as:

• Synchronization or configuration issue between Outlook & Exchange Server.
• It is absent from your Exchange or Outlook 365 profile.
• The Deleted Items folder has been renamed or relocated.

Solution

To make the Deleted Item available again, you need to fix “The Deleted Items folder is unavailable. Try the following methods to solve the previous problem:

• Subscribe to Deleted Items folder.
• Create a Deleted Items folder manually.
• Reset Outlook folders
• Repair Outlook

5. Emails Showing in Outbox on the Server but Not Visible in the Outlook User’s Outbox Issue

Another issue users encounter due to discrepancies between Outlook and Exchange Server is the invisibility of emails sent in Outlook’s Outbox that are visible in the Server’s Outbox. Such conditions could lead to a lack of updated information, leading to decision-making delays and lower productivity.

Solution

To solve the emails not showing in Outlook’s Outbox issue, you must execute the following techniques:

• Turn off the Cached Exchange Mode.
• Disable antivirus
• Rebuild the OST file.
• Utilize the Microsoft SaRA tool.
• Repair Outlook profile.

6. Outlook Data File Cannot Be Accessed (Error 0x8004010F)

You may face this error when Outlook cannot access the OST file linked to your email account. It usually happens when there’s a problem with your Outlook profile or data file location, preventing Outlook from sending or receiving emails. Below are some reasons for this error:

• Corrupt or damaged Outlook profile
• Incorrect file path or location
• Exchange or IMAP connection issue
• Antivirus or Security application incompatibility

Solution

To fix Outlook data file cannot be accessed (Error 0x80040120F), perform the below methods:

• Create a new Outlook profile
• Add your account and set the new profile as default
• Locate or re-link the correct data file
• Delete and rebuild the OST file
• Temporarily disable antivirus software

7. Recurring OST Corruption Loop Error

When your Outlook keeps crashing or restarting unexpectedly, your Outlook data file gets corrupted. After fixing this issue, your OST file will repeatedly get damaged or corrupted with error messages when facing recurring OST file corruption loop issues. You can fix it once the issues return after some time, which causes data loss and affects Outlook performance. A few common causes are:

• Unstable internet
• Large OST file size
• Corrupt Outlook profile
• Mailbox migration or server mismatch issue

Solution

To fix the “recurring OST corruption loop” issue, execute the below proven methods:

• Delete and recreate the OST file.
• Create a new Outlook profile
• Limit OST file size

Common OST File Error Due to Storage Limitations

Microsoft allocates 50GB as the default storage space for every OST file to store mailbox data, including emails, calendars, contacts, attachments, tasks, notes, etc. However, this storage quota is often reached, creating issues like a full mailbox. The accumulation of old emails and large attachments is usually the reason for hitting the size limitation. Common OST storage-related problems faced by Outlook users are:

1. Outlook Mailbox Full After Deleting Issue

Outlook has a preconfigured storage quota for every user. This storage limit is often utilized by the emails received and accumulated over a long period. Therefore, users regularly delete old obsolete emails and their respective attachments from their mailboxes.

However, sometimes, even if you have removed the unwanted old emails and data items, Outlook still throws the error saying the mailbox is full. The occurrence of such a scenario will stop the incoming & outgoing emails until adequate space is available again.

Solution

To clear the storage and resolve the Outlook mailbox full after deleting issue, you can try the following troubleshoots:

• Empty the Deleted Items folder manually
• Utilize the Outlook Clean-Up tool to delete obsolete emails effectively
• Archive the emails to save space
• Compact the OST file

2. Outlook Feels Laggy or Pauses Due to Large Outlook Data File

As we learned earlier, the OST file contains all the files & folders along with attachments stored in the Exchange Server. To make the latest content available offline, the OST file is continuously updated and synchronized with the server.

However, often, the size of the OST file exceeds to such an extent that it begins to hinder Outlook performance. An oversized OST file would take longer to load when Outlook is launched, causing users to experience laggy Outlook performance. Also, it would slow down the process of OST backup and migration.

The OST file could become massive in size due to several factors, such as:

• Large email attachments
• Numerous data items in shared folder.
• Accumulation of large number of old obsolete emails.
• And more

Solution

To restore the Outlook application performance, you can utilize various methods to fix Outlook application lag issue. Some of the proven techniques you can try:

• Archive Outlook items
• Disable Cached Exchange Mode for Shared Folder & Public Folder.
• Setting a suitable items per folder limit.
• Move unwanted emails to a separate PST file.
• Permanently delete obsolete emails.

Users have also reported receiving emails regarding Outlook storage quota limit extend. The email states and asks the user to review and resolve the “Your mailbox is almost full” issue.

Common OST File Errors Due to Issues with Exchange Server

The problem doesn’t need to be always on the client-side. Sometimes, the root of the issue is the server facing some technical problem that might be halting your email process.

One of the most common error users find in Outlook due to server-side problem is listed below with possible solutions to help.

1. Microsoft Outlook Cannot Connect to Server Error

Outlook is an email client that you use to manage your emails, but the Exchange Server does the backend processing. Therefore, the server must properly function to ensure a smooth email flow.

However, sometimes users get interrupted with errors such as “Outlook cannot connect to the Server” or “Exchange Server is unavailable”while accessing Outlook. This error indicates that Outlook has failed to connect to the Server, preventing users from sending & receiving emails.

The issue can be observed due to several reasons, the major ones are:

• Server is down (due to maintenance or technical problem).
• Corrupted OST file or Outlook profile.
• Using outdated Outlook version.
• Internet connectivity
• Incompatible Outlook add-ins

Solution

To fix the Outlook cannot connect to the Server issue and re-enable the original mail workflow, you can practice the following procedures:

• Update Outlook to the latest version.
• Verify availability of adequate internet bandwidth.
• Avoid installing incompatible Outlook add-ins.
• Contact the Microsoft Exchange Server support to ensure that the Server is up and running.

2. Error 0x80040154 (Class Not Registered)

While opening Outlook or sending/receiving emails, you may face this error because your Outlook failed to access a Windows COM library or feature. Generally, it’s a key file which is either missing, broken, or not properly connected to Windows on which Outlook depends. A few causes for this error are:

• Corrupt Outlook installation
• Unregistered DLL/COM components
• Conflicting Office versions
• Faulty add-ins
• Incorrect registry settings

Solution

To resolve the error 0x80040154 (class not registered), execute the below effective methods:

• Repair and update Microsoft Office
• Re-register Outlook or Office components
• Check and disable faulty add-ins.

Conclusion

It is safe to assume that Outlook will be the preference of many individuals and organizations for many years to come. Therefore, Outlook users must be familiar with different common issues/errors in Outlook. This blog has covered all the major Outlook issues along with possible solutions.

However, if the issue involves severe corruption, we recommend using the Kernel OST to PST Converter tool to safeguard your mailbox data. The tool is equipped with powerful algorithms to achieve 100% data recovery securely. The tool maintains the original file & folder structure with complete data integrity.