Outlook - set of folders cannot be opened - unable to fix this error via any method

Anonymous

Hello,

i have an issue i've been unable to resolve for a few weeks, maybe even months now.

I was setting up a new All-in-One PC for an employee at a company we do IT support for. The setup went without a problem, he has Windows 10 OS and a Microsoft 365 Business Standard license.
A week or two go by and he informs me hes getting the known error when opening Outlook - The set of folders cannot be opened. To simplify, I decided to create another mail profile. This seemingly resolved the issue but I get another call from him a few days later saying the same problem has occured. We repeat the process and create a 3rd email profile. The same error pops up again, even sooner (maybe a day or two). The most peculiar thing is (he has 3 or 4 profiles at this point) that if I keep swapping between the profiles randomly and trying to start Outlook, lets say 1 in 20 times it actually starts up.
So I start troubleshooting the issue with everything I could find on google.

A list of possible solutions I've tried to far:

Starting outlook in safe mode - still does not start
Disabling add-ins - did not help
Reinstalling Office365 - did not help
Repaired Office365 - did not help
I believe i've tried some other repair/scan tools but nothing ammounted to anything

At this point I figured it might have to be something on his domain profile, so we delete the local profile and recreate it, the error still appears.

We replace his new PC with his older one on which everything works without any problems. We try creating a local account on his co-workers account, Outlook works fine there.

So a few days ago I decide to just reinstall the windows again hoping it would solve the issue (I did the reset with keeping the personal files). I install Outlook, it opens up. To test it out I close it down and try to re-open it - im hit with the error. I create a new profile again and manage to open Outlook exactly once, when i close it down and reopen the error hits me again. Just to make sure i repeat the process a 3rd time, same result - so in short whenever i create a new profile i manage to start up Outlook exactly once before the error appears.

At this point I'm out of ideas on what to try, I plan to bring another machine, domain join it and create his profile on it to see if the problem repeats - so far this only happens on 1 machine, on 2 others in the same domain it works fine.

Is there any reason this could be a hardware issue? Because thats the only thing that somewhat makes sense to me altho on the other hand I can't imagine it being hardware related. The OS and O365 are all updated.

Thanks for any advice or input in advance

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Answer accepted by question author

Anonymous

Had the same problem

These steps fixed it.

If updating the Outlook application was not able to fix the error in Outlook “the set of folders cannot be opened” then you have to recreate the Outlook email profile. This method has helped many users to fix the error.

Go to the Windows search bar and type regedit. This will launch the Registry Editor.
Then, navigate to Computer\HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\16.0\Outlook\Profiles (Outlook 2019,2016)
Now delete all the folders listed under Profiles.

Note: If you are using a different version of Outlook this will change as follows. Computer\HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\15.

  4. Restart the computer.

  5. Relaunch Outlook and recreate your email profile.

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75 additional answers

Anonymous

2023-07-27T18:50:17+00:00

Whoa! Just telling someone to delete things without telling them the ramifications of deleting is reckless. What happens to the data that they the profile used? Does it get deleted too? can it still be accessed? Complete information should be given so as to not put someone in a worse condition than they arrived in. This should only be used with a OST file not a PST file. With an OST file all information is stored on the server and will be downloaded again.

In a PST file, For example deleting the keys under profiles you will lose access to any rules that you have set and all email addresses that you are using in this profile as well as signatures etc... Creating a new profile will not reconnect these things to the new profile for it will have a different unique identifier that does not correspond to the old one.

The prudent thing to do would be to export the profile (regedit) for a backup, then delete the keys, restart the computer, start Outlook then shut it down when it asks to add a new profile. Use regedit to import the keys to the original location. This should fix the issue for those who use more than 1 email address in their profile along with rules and signatures etc... and you will still have your rules and signatures etc...

If you have no data and want to start over again, just delete the profile data and then recreate everything that you need including email address, associating it with the previous data file and recreating any rules and signatures.
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Anonymous

2022-02-21T15:48:02+00:00

I have been dealing with this same issue for 5 months now. I have had Microsoft on the phone several times and on my computer trying to fix it. They can not. They need to go back to a previous version before last June and stay there until they figure it out.

If I close Outlook, I have to reload the profile and let it all reload again.

This time I did not accidentally hit the x button, outlook just closed on it's own.

Does anyone out there know of a different program that allows different computers and users to share emails like outlook does? I would change in a heart beat.
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Anonymous

2022-02-18T08:25:52+00:00

Hi, I have encountered the same problem with Outlook not opening since updating to Windows 11. It (Outlook) works fine on my Windows 10 machine, but for some reason I get the same error message every time I try opening on Windows 11.
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Anonymous

2022-01-31T16:35:36+00:00

Hi
I have the same - have done all the same including repair the PST and OST files. I now have reports that there no issues on any of the files but it still gives me the same message as above. I have tried re-installing Office with no joy.
I did have a corporate account which was removed, and I used to just ignore and would be able to get into Outlook no problem. Now it will not let me in at all.
Should I try setting up a new profile?
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