By default the HotChocolate GraphQL server does not expose any exception details when an errors occurs. The only information you get back is the following:
This is of course a good idea from a security endpoint but not very helpful when you want to investigate a problem.
In order to automatically add exception details to your GraphQL error you can switch the execution option to include exception details:
Remark: When a debugger is attached this behavior is changed automatically and exception details are included.
More information: Error Filter - Hot Chocolate - ChilliCream GraphQL Platform