The Roblox error 500 can be one of the indicators of an on-going server problem so what you have to do is to check the game’s server status.

Fix #3: Check Roblox server status. Sometimes, a Roblox game may not launch or return an error like the HTTP 503 service unavailable when you try to open it because of an on-going server trouble.

High Ping can occur due to many reasons. Check your internet connection and cancel all downloads to fix the High Ping issue in Roblox.