[JaTochNietDan]

Check your server_log.txt, and I would be assuming that most hosts are using Linux for security and performance. If you use any plugins, make sure you have the Linux versions of the plugins in the plugins folder, also remember that Linux is CasE SeNsiTiVe so you will need to make sure that all of your files are created to suit those needs. The standard is keeping all files lowercase.

I hope this helps.