Hi there!
During the past week or so, I have experienced around half, if not more, of all the games I’ve been to have crashed (window is all white, and the “An error occoured” popup message appears).
This have primarily happened while having the ROBLOX Player window minimized. I note one time where it happened while trying to chat something.
I am using Windows 8.1, and depending on situation, I can both choose to click the icon in the taskbar or use Shift + Tab to change focus from ROBLOX. I do not know of others of the people I speak to daily who seem to have this problem.