Invalid data on form submit

Hello,
I have a single record form with about 200 fields on it.
When I enter some data and click ‘save’, I get an error “invalid data”.
How can I determine what field is generating the error? Is there somewhere in
View | Data in Session that will identify the error field?
Thanks

I have already selected “highlight field with error” but nothing get highlighted.

Generally that error is a PDO exception. Meaning that a writet to the database isnt going well.
as far as I know you can turn mysql logging on. That should give you the error in the logs.

my approach to this would be to create a new form based on the same table but only select a minimum amount of fields and test that. Then expand the field list and check again. You get the idea. Keep going until you get to the field that is the culprit.

so why am I getting this same error on MENU app ?