I know that there are already some threads about this issue. Here is the full error for anyone who's not familiar:
You don't have permission to mount the file.
As many others have pointed out the ISO file does indeed mount anyway. Based on that the error message appearing seems to be the real issue. I work in software and if an error message is being produced in error it is a bug. It is obviously just an annoyance since it does not affect the desired functionality of mounting the ISO file. I would like to know if this issue is being addressed by Microsoft or if there is a manual fix that will prevent the erroneous message from appearing.