Can't synchronize - After FreeFileSync.exe properties change to run as admin, the source network drive can't be selected

[davidkrepinski]

I'd like to synchronize my NAS drive to an external drive (Z:), every time trying it I get following error:
Cannot set directory lock for "Z:\".Cannot write file "Z:\sync.ffs_lock".Error Code 5: Zugriff verweigert (CreateFile)
One solution I've found here is to Change in properties of FreeFileSync.exe to activate the function "run it as Administrator".After I do that, FreeFileSync doesn't find my source drive anymore (NAS).
Do you have any solution for this?
Thank you!
David