Lost connection C1 mapp to my HD

I have a folder in C1 22 with about 1100 images but none of these are displayed in C. If I right-click on the directory and choose add folder, I can see the current directory in the explorer. Tried to select add folder but nothing happens, how do I get the link back between the folder in C1 and the files on my HD. I run iMAC with Big Sur as OS.