User can't play library file without Administrator Rights

i add a user with ALL RIGHTS but “administrator” & “view all sources”,
this user could view thumbnails in library, but when i try to play it …
on PC it shows “Enter a valid login name and password for realm” in VLC ,
on Android device it pops up a thumbnail with a gray-out play button.
but if i give this user “administrator” or “view all sources” right, then it works correctly .
I just want this user could view specific sources and play those records.
What should I do?
my netcam studio ver is 1.6.2.

Yes, I agree. This certainly acts a little weird. In principal for a user to see Library for a specific cam that user must have Library Enabled and also that camera must be Enabled. This means also that the user can see this camera live which is logic. This works for me in the web client, but is sort of weird in the windows client. Sending this to @steve for further investigation.
Maybe in the meantime you can use the web client?