Hello,
I did not work with versions of Access more recent than 2007, but have a
certain experience of previous ones, including migrating from a version
to a newer.
You will get a better view if you can execute the form_load step by step
to see when an error appears (do not forget to put the error procedure
call in comments, and re-enable it when everything is ready), and copy
the SQL code of the form request, and paste it to the request editor to
launch it : the request editor often has much clearer messages than the
execution during a VB code or a macro.
A possible issue is that a default name has changed in the new version,
or that a prefix rule has changed (being said that for instance a field
name is prefixed by its table name).
At least, this will enable you to provide more information, that will
help to solve the problem.