Is this a backdoor?

[metatablecatmaid (metatablecat)]

Ok no threat, this is a loading issue with Roblox. It has been an issue with them for a while. This is not a backdoor. It is an issue with a CoreScript

You can read more about this issue here:

Errors in console: BlackFrame is not a valid member of ScreenGui

Got this error when loading a local server: 16:50:19.088 - BlackFrame is not a valid member of ScreenGui 16:50:19.088 - Script 'LoadingScript', Line 370 16:50:19.088 - Stack End 16:50:19.089 - Disconnected event because of exception Anyone else able to replicate?