I am using Ubuntu 18.04 inside the WSL. When I
cd /mnt/c/ and then
ls, the C drive is empty.
I am not sure if it coincided with a
sudo apt-get upgrade I used inside the WSL. Could this have caused the issue?
UPDATE1: I tried to revert any package I installed today. Nothing changed.
UPDATE2: I uninstalled Ubuntu, reinstalled it an everything works fine. It must have been somehting with the symbolic links. Somehow it lost the connection to the folders inside C drive. The question is why and what.