500 error : how to find out the reason for this error ?

[SecondSight]

Hello,

This morning, I noticed my community was down with a 500 error message.

I accessed the APC and ran the support tool. It disabled applications, skin modifications, ads... Then I reactivated them one after the other. In the end I found out the problem was with the theme and I removed all theme modifications.

I had made very few modifications to the theme :

- adding a <div align="center">{advertisement="hautdepage"}</div> for displaying an advertisement banner.

- making a few modifications as indicated here :

Compared to the old theme, the new theme has more options... as if the old theme had not been updated when I last updated the community.

How can I find out what went wrong ? I'm going to have a look in the community logs. As for the server logs, they show nothing...

Thank you. :)