The following generic error message is displayed when a user submits a form:
As the error states, this means a Client Script has thrown an error during submission of the form.
This generic error is displayed to users if they do not have the client_script_admin role.
Troubleshooting the actual error being triggered will involve further investigation.
To see the error being generated you will need to reproduce the issue with a user that has the client_script_admin role.