Hi, as of today's patch for WotLK Classic, whenever I log in or reload UI, I'm getting a popup in the middle of my screen saying "Couldn't load Blizzard_CUFProfiles: Disabled".

This only seems to happen when I have "Hide Blizzard Raid Frames" turned on in Grid2—With that option turned off I don't see anything. I've tried searching for what the cause could be, but can't find anything that would point me towards what may be causing the issue.

Try out 2.3.8-wrath version.
This version should hide the blizzard raid frames with no errors.
If the option is already checked, you must uncheck and check the option.

That fixed it, thanks for the quick update!