To fix An error occurred while starting Roblox Studio, Studio details failed to create key or deploy, Reset your Router, Reset TCP-IP, Disable proxy settings, etc.

For the most part Roblox works pretty well, but sometimes you get errors like ‘Failed to Download or Apply Critical Settings.’ Figuring out the problem is a bit of a head-scratcher. Regardless ...

If Roblox is not downloading or installing on your Windows 11/10 PC, restart your PC and if that doesn't help, use the fixes discussed here.