On Thursday we reported that some AdSense publishers were having issues logging in. We thought it had to do with publishers who had a manual review on their account, but we were not a 100% sure of that.

Jennifer from the Google AdSense team posted a thread in Google AdSense Help confirming the issue and saying they have put this issue on the known issues page:

The thing is, this is still an issue for many publishers even about four days later. There is currently no estimated time for when the fix will be in place.

Forum discussion at Google AdSense Help.