I can't login to my website cms as superadmin, it state "Invalid username or password". I tried to change the password by forgot password function through mail, it shows "Email could not be sent".

I replaced all couchcms files, still no luck.

What is the problem I'm facing here?

[KK]

You may try using @trendoman's method from the following thread to reset your creds -
viewtopic.php?f=4&t=10223

Hope it helps.

thanks KK. Worked like charm.

But may i know why the sudden i can't login with my own creds? it just happened with no reason.

[KK]

But may i know why the sudden i can't login with my own creds? it just happened with no reason.

I can't think of any reason except that incorrect creds were being inputted (or perhaps the caps lock was on).

impossible. both admin accounts are failed to login. it is the correct creds.

never mind. as long as the problem solved, I'll just let it go. cross my fingers and hope it never happens again....