Outlook Desktop Error "Something went wrong [657rx]"

Dear Iztok Štenta,

Since the issue began after moving your SSD to a new laptop, and only your primary Microsoft 365 account is affected while your other Outlook accounts continue to work normally, this may be related to cached credentials, device registration, or the Outlook profile associated with that account.

In this case, here are two ways I recommend you try:

Option 1:

• Go to Settings > Accounts> Work or School Access, or search for Work or School Access.
• Then click "Disconnect" to delete all accounts registered there.
• After that, launch Word or any Office app and sign in.

Option 2:

Step 1: Go to Outlook where this didn't work exactly and go to Settings > Accounts > Access work or school then intentionally add the same Outlook (the Outlook account where you were facing the issue) account, logged in, clicked "Disconnect" and then restarted the laptop.

Step 2: Please sign out your accounts from Office applications, then close all Office applications.

Step 3: Open File Explorer, paste the following path, and delete all files and folders.

%localappdata%\Packages\Microsoft.AAD.BrokerPlugin_cw5n1h2txyewy

Step 4: Search for "access to work or school" in the Windows search bar or go to Settings > Accounts > Access work or school again.

Step 5: Check if you can see your business account in "Access Work or School". If you don't see it, please select Connect and add your school account. If you can see it, please select it and select Disconnect. After that, please click "Connect" and log into your account again to register the device.

Step 6: Launch one Office application, such as Word, and sign in to your account to confirm it again.

Thank you for your patience and understanding. If you have any questions, please feel free to reach out. I'm looking forward to your update.