Hi,
I've seen this post, but I have this same problem in different circumstances:
1. When a user clicks on Login button twice (accidentally) with a very short time interval(!)
(Login process is successful but user gets "Invalid Token" error.)
2.When a logged in user has two pages open and by an unluck mistake he/she logs out from both pages.
(in the second page user gets "Invalid Token" error.)
any solution?