Hi akkarin thank you for your reply...
I made sure MD5 is false and my fluxcp latest which is working from last 2 months and all of sudden I am getting this issue. And the problem is happening when creating new account only, and the account is actually getting created but something stopping it to login automatically after creating account. I can login normally. I checked logs I don't find anything which I can fix..
edit: im adding this image hoping it could help me get the fix. thanks again.