Cannot start Microsoft Outlook. Cannot open the Outlook window. The set of folders cannot be opened.

Question

Hi. I recently had a power outage and when my computer came back on, it has not allowed to access outlook since. I have tried uninstalling and re-installing and continue to get the same error message. The message says exactly: Cannot start Microsoft Outlook. Cannot open the Outlook window. The set of folders cannot be opened. The file C:\Users\Rhos\AppData\Local\Microsoft\Outlook******@usmarketingsource.com.ost cannot be accessed. You must connect to the Microsoft Exchange at least once before you use your Outlook data file (.ost).

Please help.

I have tried signing in to the microsoft exchange countless times and have signed in under both my shared account and the original account holders account information as well and every time I get the same message. Even after uninstalling and re-installing 5 times now.

Any help you can give is much appreciated.

Thanks.

Answer 1

Hi @Rhonda Aylward ,

From your description, it may be the corrupted profile caused the problem, you may need to create a new profile, see the solutions in this article first:
I can’t start Microsoft Outlook or receive the error “Cannot start Microsoft Office Outlook. Cannot open the Outlook Window”

Hope that may help you!

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Answer 2

The similar issue is explained here https://www.magustools.com/blog/how-to/how-to-resolve-unable-to-expand-the-folders-errors-could-have-been-detected-in-the-file-xxxx-ost-error-in-outlook/ . Take a look for the possible solutions. Hope this helps. Thanks!