I made 2 Drupal installations 3 months ago and they worked perfectly. So this morning when I logged in Drupal notified me of an upgrade re. security and I upgraded. Now none of my sites are working. I get this:

500 - An error occured on this web page

The error was:

And the "error was:" is the last thing written on the page. I have the sites hosted at a hosting company and I tried to maximize all buffers and timeouts etc. but to no avail.

Running the installation gives the same error.

I tried to delete all the files and the database starting all over - same result. It doesn't work any more.

I need a great idea :-)