Issue Statement
After setting up a new on-premise D365 CE v9.0 environment, when I tried creating the first record (Contact record), I received the below error message. I wasn't able to save the Contact record.
Resolution 1
On the app server the C:\Program Files\Dynamics 365\Server\bin\assembly folder is not inheriting security permissions from C:\Program Files\Dynamics 365\Server\bin. Enable inheritance and you'll be able to save the record successfully. Inheritance added the following users to ntfs security: all application packages, all restricted application packages, creator owner, system, trusted installer. Those were not there when inheritance was disabled.
Also ensure that the deployment administrator has full permissions on the bin folder C:\Program Files\Dynamics 365\Server\bin.
Resolution 2
Ensure the deployment administrator has full permissions on the bin folder C:\Program Files\Dynamics 365\Server\bin.
Resolution 3
Ensure CRMAppPool account has full access on bin folder C:\Program Files\Dynamics 365\Server\bin. Reset IIS.
