HTTP ERROR 500 - any solutions?

Is there any way to know why it suddenly gives me this error?
www.bulkmania.it

works ok for me in UK

Works for me too in RU

Hello @f.aureligmail.com

Could please share more details on jack(at)technogiq(dot)com regarding the error.
I have check the bulmania.it, but seems no error.

Looking forward to your response.

Regards
JACK

I restored the previous day’s backup and everything was fine, thanks