Check your database connection :)

If it's intermittent it's most likely the database connection - if you're on shared/cheap hosting you're probably limited to the number of connections and going over.

Yes Matt you are correct.

look into you apache error_log for messages marked -->
    Fri, 12 Oct 2012 07:23:16 GMT
which is what the message is trying to say ;)
the ' 1350026596 ' is the timestamp of the error..
unfortunate but that's all elgg says ;o( 
although at that moment of the error..
there's more info available -> about what's happened. 
after you've got the apache_log message 
-- then we can figure out what is happenning.. maybe 
the apache error_log will be (usually is!) datailed enough.

i am using arvixe as my hosting account.!!! One that was recomended on elgg hosting page.

how do i chk my database connection its working fine because after 5-10 min of fatal error its start woking again.

@happy gupta the problem is not with elgg the problem is with your hosting company, data base fall error, mysqldb not responde at that time

@happy gupta

I just contacted you via Private Message. Please read it so I can help you with your issue.

Regards,

Rodolfo Hernandez

Arvixe/Elgg Community Liaison

I've just accessed my site and I've encountered exactly the same problem

@MRR33: read Dhrup's earlier comment. You must check your error log to see what's going on.