If we had a link to the site, we could at least see what the cookie domain and path were. Or, he can tell us what they are in AdminCP > Settings > Options > Cookies > Cookie Path and Cookie Domain. (Of course, if he can't login to the admincp, then he can't, so a link to the site would allow us to view them.)

Are you logging into the admincp using www.site.com or just site.com? Try logging in using the other one.

Ahhh, gotcha. :)

You can change your cookie prefix in your config and that will basically clear/reset your cookie cache.

I've had something like tis happen before. It seems to be connected to having logged in with a test account. Have you done that recently? I think logging out of that account might help if so.

I think You installed That Plugin

https://vborg.vbsupport.ru/showthread.php?t=217368

Disable Plugins From the config.php and then check if it work Then go to The Admincp >> Vbulletin Option >> AdminCP access

Then Add Your Id on number on AdminCP Allowed User Ids...

Then Unable The plugins

Sorry for Bad English but i want to Help.... !!!