Can’t login with firefox 40.0.2 [SOLVED]

I can log into using my usual user name & pass with ie, chrome, MS edge etc.
But when I try to do it with Firefox 40.0.2 it tells me I have entered the wrong info & to reregister.
Never ever had any problems with FF & this forum before
Very strange indeed
Answer #1
Clear cookies and try again
Answer #2
Clear cookies and try again
Tried that but it didn’t help. Must be a glitch with the latest firefox.
I will uninstall it & install a new copy then see what happens.
EDIT 1: Just tried another Firefox install & got the same wrong password message.
Got to wait 30min before I can try again.
Could be that Pesky “Sid” cookie too.
EDIT 2: OK, I made it in with firefox but only just.
First try with cleared cookies & I got the same wrong password error.
Second try with cleared cookies I got the same password error again
So before I tried again I did a dig around in firefox & found the dreaded sticky Sid cookie was still there.
I had to remove the phpBB_WBB_Sid cookie manually because it doesn’t get removed when you clear your browser cookies using FF.
Once I worked that out & got rid of it,,no more problems, signed in as usual.
Answer #3
Not the dreaded Sid cookie
Thanks for the info !