

If you find the PST file in the original location, it indicates that the PST file is corrupted. If you can’t locate the file, you can recover it from a backup (if you have it). This may fix the “Output file not valid” issue. If you are able to locate the file, you can move it back to the original location and restart Outlook. Otherwise, you can search for the PST file by using the Search function in Windows. If you had moved the file intentionally to another location, you may know the exact location. If you can’t find the PST file in the location configured in Outlook, it means the file is moved to another location from its original location.

Note: You can also note the path of the PST file and reach the folder manually. Select the PST file and click Open File Location
