Forum Discussion

Copper Contributor

Mar 17, 2026

Solved

Gmail sync issues within Outlook Classic

Yesterday, my Gmail folders stopped or failed to sync within Outlook Classic. I went through a number of steps including removing the account, re-adding it but now the sub-folders have disappeared co...

LisaHendrickson
Mar 18, 2026
Hi, there is a global security update that is changing the credentials for your Gmail account with Outlook Classic. You need to do two things: Here is the link on how to do it from the Microsoft site. I'd skip down to the manual fixes:

https://support.microsoft.com/en-us/office/unable-to-add-a-gmail-account-to-classic-outlook-4d9530c5-3f40-4e6d-9b45-4477f160828f

LisaHendrickson

MVP

Mar 18, 2026

Hi, there is a global security update that is changing the credentials for your Gmail account with Outlook Classic. You need to do two things: Here is the link on how to do it from the Microsoft site. I'd skip down to the manual fixes:

https://support.microsoft.com/en-us/office/unable-to-add-a-gmail-account-to-classic-outlook-4d9530c5-3f40-4e6d-9b45-4477f160828f

KonradSobolewski

Copper Contributor

Mar 19, 2026

It works on one computer with a still-active Gmail account in Outlook, but not when a Gmail account is removed (on the second computer). I have deleted the OAuth lines from the registry on both machines, but I still get this error when trying to add a Gmail account. I think the reason might be connected with access to localhost (connection to localhost:8011 was reset):

This is the last step of the procedure. Antivirus turns off, doesn't help. Of course, I have checked access to Gmail for Microsoft Apps.