Question:
When a user is trying to run an Ad-hoc Query containing fields from the Change_Request table, why does the report display an error: User does not have access to the table?

Answer:
This is working as designed. The users who are trying to run the report are Admin users. By default, Admin users do not have access to query Change Request tables, and as a result, they see the error when reporting on change_request. If this is required, the users need to add the appropriate Inbox Task Groups to the relevant users on the User's Page, as shown below:

Related Documentation:
Veeva Network Online Help: Working with inbox task groups
Thank you