Outlook 2019 Not Working. Missing .ost file – Some quick fixes

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 are going to discuss in this blog about a situation where a user does not able to start or run Microsoft Outlook 2019 due to “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. This 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.

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:

  • This errors may occurs due to bad network connection or Outlook configuration issues
  • You may face this errors due to unexpected shut down of your system
  • Hardware failures can be the causes for errors
  • Intervention of third-party add-ins may be the reason for this error
  • Due to the recent Office updates you may encounter error
  • This error may pop up on the screen if you have an 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 as well as the network connection, to know if there is a problem in it. 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 such external hardware and remove it, if it is not vital to your system. If there is any requirement of the hardware, 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 provides extra functionality to an application, but sometimes, this 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 are required to follow these steps in the following order given below.

    1. Launch the Outlook in safe modeusing‘Outlook/safe’ in the Run dialog box
    2. Select the Outlook profile to start the program even further
    3. If you see that the program is running in safe mode, then the add-ins are faulty, you need to remove or disable it.
    4. On the Outlook application interface, Click FileOptionsAdd-ins.
    5. Go to the right pane of the Outlook interface and Select COM Add-ins from the Manage drop-down menu. And click Go.
    6. In the COM Add-Ins dialog box, unselect all the add-ins checkboxes and then click OK.
    7. 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 as well.

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 sometime affect the program unfavorably. Therefore, we recommend that you, to reinstall the previous version of the program if an Outlook error occurred 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 is able to scan and fix errors in both Outlook data files (.ost and .pst). This 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, just 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.
  • Exit the application once the repair is completed

Recreate OST File

This 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.

  1. Close Microsoft Outlook application
  2. Go to the Control Panel of your system, and then click Mail option
  3. Now a Mail Set-up page will open, here click on Show Profiles option
  4. Choose Exchange account profile and click Properties and then click Email Accounts tab
  5. From the Email tab, select Exchange Account and click the Change option
  6. On the Change Account page, make sure Use Cached Exchange Mode is selected. Then click the More Options option
  7. Go to the Advanced tab and click on the Offline Folder File Settings option
  8. Go to the File section and enter the .ost file path. Click OK
  9. If prompted, enter a different .ost file name and click OK
  10. Finally, click Finish and exit Mail Set-up
  11. 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 that we have discussed above can help you to fix the problem related to MS Outlook 2019. And you can be able to access Exchange mailboxes in Outlook using OST file without facing any errors.

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