Hi,
looks like you did not set the access for your users yet. Have a look at e.g. entity TrainingEvent, attribute StartDate.
Double click on the entity.
You will find a tab “Access rules” which appeared now that you enabled production security.
Click New there and configure the desired user access.
Useful:
https://docs.mendix.com/refguide/app-security/
Good day,
When you set you application security to production level it checks your user roles and what they have access to. Most of your errors are from user roles not having entity access.
To fix this go to the entity and give your module user role access to the entity as it needs. Then go to application security, assign your module user roles to your application user roles and that will solve your problems.