Yessss.....I am also getting this problem...I cleared cache, history and everything but still...its of no use

@Jaiswal

Hello Subham Delete old installation of elgg and its database it does not create admin account when you have installed it with firefox.

Solutuion 1: Reset Firefox and its settings if it does not work uninstall it and use fresh install of firefox after that install fresh elgg.

Solution 2 : Use freshly installed different browser to install new elgg installation. I tried IE and Opera both worked and let me login.

100% tested let me know which solution worked for you

In my case,log in problem comes after some days of last login.Why is it so?
@cicor ,I will try your suggestion.

If you are not willing to use profile manager, then you should develop a plugin yourself for this.

• You have to extend the registration form view to include additional fields. 
• Then you have to getthis input value either by overriding the action file or by using an event hook.

http://docs.elgg.org/wiki/Login_token_mismatch_error

Thanks its worked