Hi,
I am using My Cloud PR4100, OS5, fw 5.11.112 ( newest)
This device oftens encounter “Offline Driver” and can not create or delete folders.
Also, since upgrade OS3 to OS5, I have not been able to move files between level 1 folders.
If you haven’t done so already you may want to see the dedicated subforum for your PR4100 device where there may be similar discussions (found via the forum search feature, magnifying glass icon upper right) to your issues and where people more familiar with your device may be able to assist.