Using classic Outlook for Windows in business environments
I am another person affected by this problem since last week. The workaround from @JariVolanen did not help. I am currently in a support chat. According to support is a known issue and engineering team is currently working on the solution. Below is the workaround from Microsoft, which did not solve the problem for me.
Best regards
Andreas
Workaround Microsoft:
1: Remove the account from all devices and then add it again.
1: Open the new Outlook and navigate to Settings > Email Accounts.
2: Select Manage for the account you want to remove.
3. click Remove under the account.
4. when prompted, select "Remove from all devices" and wait 10 minutes for this process to complete.
5. close new Outlook
Once Outlook is closed, launch the OneDrive app, sign out and sign in to the OneDrive app on the device.
Restart Outlook and navigate to Settings > Email accounts > Add account.
Enter the email address and then select Next.
Select Next to add the account
When you have finished, check that the problem has been resolved.