Fatal error without message

[kamikaze cow]

I have been using the Coppermine to manage the pictures of a salsa community. It has run well, however, today an error message appeared and the gallery won't work. The message is this: "Fatal error:" So I can hardly figure out what the problem is. Via FTP, I have uploaded an old backup, but it still doesn't  work. Thus, this must be a database problem. Any ideas? This is the URL: http://www.salsafuerte.hu/gallery/ What can I do to save myself from uploading the pictures again?
Thanks in advance. 

[Nibbler]

http://coppermine-gallery.net/tutorial/debug_mode.php

[kamikaze cow]

http://coppermine-gallery.net/tutorial/debug_mode.php

The error message:

Code Select Expand

While executing query "delete from `sitename`.coppermine_sessions where time<1194988254 and remember=0;" on Resource id #5
mySQL error: Table './sitename/coppermine_sessions' is marked as crashed and should be repaired

I deleted this table and uploaded the older one from backup. It works fine. Thank you for help!

[Joachim Müller]

Alternatively, you should have repaired the table as suggested in the error message - won't do no harm though to delete that table and start with a fresh copy, as the data stored in the sessions table is not that important and will be regenerated.
Marking as "solved".