Image under construction AND NO SOUND


I keep loosing my way in the file-management system in Cubase 9.
Today I finished a project and wanted to move the audio-files to another folder on my HD. I usually do this in finder, and have Cubase 9 locate the files again at the next start-up of the project. But this time it went wrong.
Now I have some audio parts with the “Image Under Construction” text. Furthermore the audio is not playing.
In the pool all the files are there, and if I run the “reveal in finder” on any of them, I get to the place in finder where they are stored.

From here I don’t know what to do.
Anyone with a good idea?