One of the pages cannot be launched

I have downloaded the Concrete5 using OneClick. The ready-to-use website has several pages including a ‘Blog’ page. I have changed the name to ‘Discussion Forum’ a few days ago and continue to build and modify the page. 2 days ago, when i click at that Discussion Forum page to do editing, the page cannot be launched after waited for 5 mins. It has a Internal Server Error message, and asked me to contact I have sent emails to Dreamhost but the answers have always been asking me to refer to some comments on the Concrete5 discussion forum, but it didnt help me to resolve the problem. It has been a few days already, i cannot do anything at all.

What do i do now?