[TYPO3-english] TYPO3 site suddenly broken. What can i do?

[Martin Mädler]

Hello List,

I'm a little bit lost right now, because the TYPO3 site I'm working on 
isn't responding at all anymore (empty site and "Internal Server Error 
500" header is sent). This includes the FrontEnd and the BackEnd! The 
database is still there and seems to be complete. The server is working, 
too. Because when I drop a test php script and call it, that works.

The last thing I did was installing the doc_indexed_search (in order to 
install indexed_search afterwards). That's what shows up in the log, too 
(when I look at it with PhpMyAdmin).

What can I do to resolve this? How I can I track down what's going wrong?

Thanks!
Martin