We have an access issue that we're currently investigating/looking for the root cause. In the past, Access Checker from XRMToolbox has been helpful to us but now we're unable to use it.

When we try to retrieve access rights of a user from any entity, we are getting this error:

"An error occurred: Sequence contains no matching element"

By the way, we are still on Dynamics 365 v8 on-prem, so no check access feature yet. 

Anyone who can provide another way of checking access to records, please let me know. This will be very helpful for us. 

Thank you!