Site Users Cannot Login Urgent Help Needed

Hi,

I have a problem- my site users cannot login. It simply says wrong password/username. They can’t go any further.

Also on registration, it redirects straight back to the login page to attempt to login, rather than going to the Account Area.

The registered users do show in the listed members in the backend, but nothing else works for them.

Admin can still log in.

I can’t de-activate all my plugins as this site is a real live business.

Any help urgently appreciated.

I’m in DP 7.0.0.9