Ta Peter, much appreciated

Well we have been off-line again for about 3 hours early this afternoon but I have finally managed to get version 4.0.1 of our software up and running. The main issue was getting the database to update to the new version. I won't go in to details but it involved some anomalies with the server system configuration.

I now have a little bit of fine tuning to do but that should not involve taking the site off-line.

This is a major update so there may be some slight differences however the general appearance should be the same.
Let me know by PM if you are having any problems.

Well done, playing with databases can often present problems. Is it SQL?

Yes it is SQL (MariaDB)
Actually for the technically minded it wasn't the SQL database that was the problem but a conflict of PHP parameters in which the session variable was allocated to 3 different directories 2 of which did not even exist. Once that was resolved the program (PHP) that performed the update of the database functioned. I was on the verge of performing a long list of SQL queries by hand but fortunately I discovered the real problem in time.
It only took 2 weeks to find it 😡

I can't access the page even after I've reset my password.

Clear your browser history and delete cookies for the site?

Thank you Tim, that worked.