The error message will say " Form data invalid". This could be due to the BO.AttributeName you have deactivate as required or to an attribute of the same BO. It could be as well a required attribute you forgot to display on the Form.
The easiest way to solve the problem :
1- delete the BO.AttributeName you have set as required
2- publish the BSV
3- Create a new version
4- Recreate the BO.AttributeName with a different name, such as "BO.AttributeName1" or "BO.AttributeName2"
5- Publish and test
The problem might have occurred if that attribute is still marked as required on the database side...