jrCore 6.0.5 error
Installation and Configuration
nothing.
You could run the integrity check and try again after that, but the most likely cause of the issue is your server trying to communicate with jamroom.net and not being able to.
If you like you can send me the login details for an admin account to support at jamroom dot net and i will login and attempt the upgrade. See if I can see any reason its not working.
(enter suggestion for you to use Jamroom Hosting here)