Delete browser cache and also cookies. A local session is either using cookies, or local storage on more modern browsers, and if those mismatch to what the website expects, you won't be able to log in.
Unfortunately, you'll have to re-login after doing that.
Likely, the local session cookie had an expiration. A week, thirty days, etc. It's a security feature.
(Huh, I did learn something in those web programming classes.)
____________________________FFXI: Catwho on Bismarck: Retired December 2014
FFXIV: Katarh Mest and Taprara Rara on Lamia Server - Member of The Swarm Curator of the XIV Wallpapers Tumblr
I can't understand anyone who skips the cutscenes of a Final Fantasy game. That's like going to Texas and not getting barbecue.
and the XIV Fashion Tumblr