Thread:Project:Support desk/I edit databse mdw user and delete every user except admin, now i have a problem.../reply

Uh... you definitively screwed that up. MediaWiki uses a relational database. All entries in page history have relation with the user table. If you delete all users, those entries won't have a matching user in the user table and most likely the won't be accessible.

If you are using MySQL and you have the binary log enabled, you may recover your database to the point before you deleted those users as you can see here. But be sure to take a database backup before performing this action.

Alternatively, you may try to insert all the deleted rows of the User table by looking at the id's of Manual:Revision table (rev_user filed).

Anyway, that shouldn't be the cause of the login page. maybe you're not accessing to the Special:Userlogin page but a userlogin page?. Try accessing through Special:Specialpages.

PD: Also, for removing users you can use Extension:User Merge and Delete.