@normanfrustrated 

RE: this Class column disappeared and cannot be found. See attached screenshot.

RE: Also previously there were two buttons under the check: New Check, Save and Exit

It looks like you have enabled scaled up fonts / selected something other than 100% in your display preferences. This will mess QuickBooks up, at it can't handle such new-fangled advanced settings, which Windows has only had for 25 years.

If you return your display preferences to standard fonts - 100% scale, then it should work again as expected after restarting QuickBooks.