Need some hosted QB help (Unrecoverable Error)

Is anyone proficient with hosted Quickbooks?
I have a client that is using CloudJumper for QB hosting and every few days at least one user will get an Unrecoverable Error message. To resolve this I have to delete the QB user and then recreate them. My client is becoming extremely frustrated.

I have tried installing updates for both QB and the server itself, but to no avail.

What is causing this? And how do I stop it from happening?