Outlook 2019 Not Working. Missing .ost file

Admin Last updated on: December 19th, 2024 7 Min Read

Many Outlook errors are associated with OST files. According to many queries submitted on Microsoft forums, It is mainly happening in the latest version of Outlook (2019). Today, we will discuss in this blog a situation where a user cannot start or run Microsoft Outlook 2019 due to a “missing .ost file” error.

The Exchange account uses an offline Outlook Data File (OST) file to store a synchronized copy of your Exchange mailbox information on your local computer. The tool allows you to use all the data you have already downloaded, such as email, calendar data, contacts, and tasks, etc., whether you are connected to the server or not. You only need to connect to the server to send an email and download a new email. However, your email messages will not be sent, and new messages will not be downloaded until your Internet connection is established.

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Why is Outlook not able to locate the .OST file?

In case if you are working with an inaccessible Outlook data file due to the ‘ost file error,’ then your first task is to find out the reasons behind the origin of these errors. However, the most common causes of this error are listed below:

These errors may occur due to bad network connection or Outlook configuration issues
You may face these errors due to unexpected shut down of your system
Hardware failures can be the causes for errors
The intervention of third-party add-ins may be the reason for this error
Due to the recent Office updates, you may encounter an error
This error may pop up on the screen if you have a corrupted OST file

The above issues are not the only cause of the problem you are facing. Nevertheless, you can try to solve the problem with different solutions. Let’s discuss the methods that can be used to solve the “Missing .ost file” error issues.

Check the Network Connection/Configuration Settings

First of all, you need to check the server and the network connection to know if there is a problem. Apart from this, you also have to make sure that the configuration settings are correct.

Check and Replace Hardware Connections

If a problem occurs after attaching any recent hardware, check external hardware and remove it if it is not vital to your system. If there is any hardware requirement, check its authenticity and replace it with a new one (if it is damaged or corrupted).

Remove/Disable faulty Outlook add-ins.

We always think that Add-ins provide extra functionality to an application, but sometimes, these add-ins may interfere with applications such as Microsoft Outlook and its synchronization process. Therefore, it is valuable to disable or remove faulty add-ins from your Outlook application if you’re facing any problems.

To disable faulty add-ins in Outlook, users must follow these steps in the following order given below.

Launch the Outlook in safe mode using outlook/safe’ in the Run dialog box
Select the Outlook profile to start the program even further
If the program is running in safe mode, the add-ins are faulty; you need to remove or disable them.
On the Outlook application interface, Click File → Options →Add-ins.
Go to the right pane of the Outlook interface and Select COM Add-ins from the Manage drop-down menu. And click Go.
In the COM Add-Ins dialog box, unselect all the add-ins checkboxes and then click OK.
Exit the Microsoft Outlook 2019 application and then restart it.

Note: If the Outlook program started at the end of the final phase, it concludes that one or more add-ons were responsible for the problem, which you can track by enabling the add-ins one after one and by restarting the application.

Un-install Recent Updates to the Office Program

We all know that Microsoft develops frequent updates to add the latest features, services, bug fixes, etc., but these updates sometimes affect the program unfavorably. Therefore, we recommend that you reinstall the previous version of the program if an Outlook error occurs after the last update. After installation, restart Outlook.

Repair Corrupt Outlook Data Files

As we have already mentioned, one reason for this problem may be corruption in the .ost file. In this case, you can take the help of this SCANPST.EXE utility to identify the errors in your corrupt Outlook OST data file and fix the errors effortlessly. This program can scan and fix errors in both Outlook data files (.ost and .pst). It can only solve issues of minor corruption errors in files limited to 2 GB.

The location of scanpst.exe depends on your version of Outlook; here, we only talked about Outlook 2019.

Office 365 / Outlook 2019 / Outlook 2016 Click to Run

any Windows; C:\Program Files\Microsoft Office\root\office16\

The default location of the Outlook data file is as follows –

Outlook 2010, Outlook 2013, Outlook 2016, Outlook 2019 and Office 365

C:\Users\%username%\Documents\Outlook Files\

First, it is recommended that you back up your Outlook data files as a preventative measure. Users can then go to the default location and double-click the scanPST.exe to scan.
In the open application, click Browse to add a .pst or .ost file to scan errors. Click Start.
It will start scanning the added Outlook data file. After the scan is complete, you can see the error and its details.
Then click the Repair option to fix an error in your data.
Once the repair is complete, close the application.

Recreate OST File

It is another trick to solve the Outlook application issues related to errors. The .ost file recreation process is as follows. You can follow the below-mentioned steps one by one to recreate a new OST file.

Close Microsoft Outlook application
Go to the Control Panel of your system, and then click the Mail option.
Now a Mail Set-up page will open; here, click on the Show Profiles option.
Choose Exchange account profile and click Properties, and then click Email Accounts tab.
From the Email tab, select Exchange Account and click the Change option.
On the Change Account page, make sure Use Cached Exchange Mode is selected. Then click the More Options option.
Go to the Advanced tab and click on the Offline Folder File Settings option.
Go to the File section and enter the .ost file path. Click OK
If prompted, enter a different .ost file name and click OK
Finally, click Finish and exit Mail Set-up.
Now you can start the Outlook application. This time you will get a new .ost file with synchronized Exchange mailboxes created automatically.

We sincerely hope that the solution discussed above can help you fix the problem related to MS Outlook 2019. And you can be able to access Exchange mailboxes in Outlook using OST files without facing any errors.

If this method fails, we would like to recommend a specialized tool named OST to PST Converter tool that effortlessly repairs users’ OST files that are highly corrupted. It is capable enough to recover specific data from OST mailboxes to PST file format without the hassle and allows you to import it into Outlook at any time. It is the best way to recover and repair OST data files. Therefore, try this effective and reliable software as your final solution.