Interesting observation on Error # 1116 -- Too many windows open. While testing for an error handler, I got hung up on error 1116. This error would never go to my error handler. You always get a VFP error message box with "Too many windows open" message and an OK button. Try the following in the command window:

lError = .f.
on error lError = .t.
error(1116)
? lError

lError remains false. All the other errors observe the error handler. This is easily discovered putting error[i] in a FOR loop with an ON ERROR condition. I was populating an errors table with all the VFP error numbers and messages for each error[i] that returned a message{} that was not Error code is not valid.