Error 500

Hello,

My users and myself have being noticing that our forum is sometimes inaccessible, today again, some of the time only an Error 500 page show up instead of the forum.

When that happen, i can no longer log to the "edit" of the website itself.

Is there something we did wrong somewhere or is there something we can do about it?

the website is : skyeden.altervista.org and the forum : skyeden.altervista.org/forum

[Gianluca]

Can you please post the time of the day it happens if it will happen again?

Please Solve my this problem
http://pkgsm.altervista.org/
This error may be due to an erroneus .htaccess file, added by you or by a script in the current directory.Screenshot_1.jpg

[dapeco]

@pkgsm: do you have add plugins or you have done any modifies to wordpress installation?