Can't Acess Files in former Nexcloud directory after reinstallation of desktop client

OS: windows 10

Because of very strange problems with my nextcloud client I completly uninstalled the client (with Revo-uninstallter) and made a clean reinstall of the client. The nextcloud files are in a new direcory. But I can’t access most of my files in my old nextcloud directory. (cann’t read file error)

If i want to move the direcory to a different location i get:
Cloud file provider not running

if i want to move a file:

Were you using full sync or virtual files?