Pyramid Explore Internal Server Error 500

Hello,  

I hope I'm not asking a repeat question but I have been having this issue for the last few days when trying to complete the walkthroughs on Pyramid Explore. In the morning, I log on and everything works fine but at around 1 o'clock after lunch I am met with this error.  It seems to be pretty predictable, happening after around 2-3 hours of being logged on - has anyone else had this issue?

Thanks!