Unfortunately, there is no access info to connect to your server in Helpdesk, so I cannot tell you exactly what is wrong.
Anyway, the plan for you would be
1) Contact hosting team and ask them restore your store from recent backup
2) Please let me know what module you were trying to install and I will try to recreate the problem on my local installation
3) You can drop a message to our tech support team at
support@x-cart.com and discuss the problem with our engineers