In Ubuntu 18.04, Bionic Beaver, if you are using xrdp for remote access, you may notice a directory called "thinclient_drives" appearing in your home directory. In the permissions it may show a bunch of question marks, which looks scary.
There seems to be a bug in xrdp code which attempts to share drives, clipboard and other things. It is creating this directory and not mounting it correctly. Here is how to get rid of it.
Edit /etc/xrdp/xrdp.ini. Update the allow_channels setting to say allow_channels=false.
After saving the change, remove the spurious thinclient_drives directory. If the system will not allow you to remove it, first unmount it with
sudo umount $HOME/thinclient_drives
You will not be able to use shared drives, clipboard, and so on, but those do not seem to be working anyway.