Administrator Permission: As for fixing the abovementioned error, the Administrator Permission is usually at fault and gamers can fix it by launching Roblox with the Run as Administrator permission.

So, make sure to check your internet connection whenever you are unable to join a private server. Contact Roblox Support If you are still unable to join the private server on Roblox, we recommend ...

While this is the generic message for a server-side issue, there are a few tricks you can try to fix the issue. Check Roblox Server Status Take a look if servers are currently down.