I have code in my Form's Property Sheet [On Key Down] event which sets the focus to the first field in a subform if the user presses tab in the last field of header data.
It works fine as long as the user makes no mistakes in entering data in the last header field. That field is a date and if the user enters a badly formatted date and presses tab, they get a run-time error 2110 "Access can't move the focus to the control xxx"
Then, if they press end, it will let them go back and adjust the date but it seems to hang on to the initial bad value and repeatedly say "The value you entered isn't appropriate for the input mask." even if it is now a good value.