Thread:Project:Support desk/Upgrade from MW 1.18.1 to 1.23.5 broke sysop and Bureaucrat users functionality/reply (5)

It appears I have an answer.

In MediaWiki 1.18.1 logging into EDir created user names using the EDir convention: Uppercase Uppercase lowercase rest of username.....

Logging into Upgrade MediaWiki 1.23.5 forced Username to: Uppercase lowercase rest of username....

Simply editing all usernames in DB to be Uppercase first character only fixed it.