I thought there was something fishy going on.
I figured if you would try relocating your templates and setting up SONAR to reflect that, some solution would present itself.
Good to hear it's working for you, now.
Because of the user control you mention, sometimes a user has to take ownership or full control of some folders or files or some users or programs can't access them. Because of some level of access control we ourselves apply, there is limited access to data on our PC. It's a security feature that sometimes can be a pain in the butt. At the least, there are two user categories you have to be concerned about, yourself and everyone.
Maybe you can try to be more careful about what access control you apply to certain files and folders, in the future.
It's great that you explained the solution, in case this problem pops up for another user, sooner or later.
I'm glad it's working for you, now.
Cya around.