On occasion I've had login problems on the odd site or two with Chrome. Clearing the cache and cookies resolved the issue (I think it was a corrupted cookie that was the problem).
After an upgrade suddenly seems working then he stopped. Tried to install a clean installation, but after login simply doesn't appear any error message.
Only thing I can think of is if you have a very overzealous ad blocker which is blocking the use of the word "admin" because it contains the word "ad".
You'll have to try disabling browser extensions or using a different browser to see if that solves the problem.
On occasion I've had login problems on the odd site or two with Chrome. Clearing the cache and cookies resolved the issue (I think it was a corrupted cookie that was the problem).