Error! Your username or password was incorrect. Please try again.

I'm getting this for all profiles and for as admin account as well? have just recently moved server but this came up after a few days of everything being fine?

Has anyone have any ideas on ho to solve this please?

first try replacing member.php file if doesn't work, drop all rows from sys_sessions

Many thanks for the info

none of that seemed to work either

Has anyone else any ideas?

I am getting this when I tried 7.1, only way to login is to click the link to the administration panel after a fresh install, else it always fails with login. I have no idea yet what it is.

need to make sure your database has the correct lang format required for dolphin. also, have you tried to troubleshoot, install dolphin on a subdirectory, then edit the header.inc file to point to your existing database, see if that resolves the issue, if so, then you have a corrupted file, was the cache cleaned when you moved servers? also that a plugins/htmlpurifiiers can give you some problems.