This occurs when you are disconnected from the BI servers/databases. Not saying it is acceptable, but that is what is happening. As you have mentioned, a restart will fix it, along with sometimes simply going back to the main menu solves it for me.

Can you specify which game mode this is occurring on?

Also, you can be in a helicopter flying over and still hear the waves as though you are standing on the beach.

File patching is now enforced for execVM/loadFile etc.

So either pack your loose files (makepbo lets you pack loose files without needing a config file) or use -filePatching on the server.