Hi @naddy,
Could you elaborate on this „it happens even without connecting to any device.“ did you mean even without connecting to spacedesk?
For your Blackscreen problem, do you maybe have Nvidia ShadowPlay installed on your machine?
Could you please check for any incompatible software, just run the spacedesk Driver Console -> Diagnostics -> Incompatible Software Products.
For the files you sent, unfortunately, the files exceed the allowed size.
Could you maybe upload the zip files in the Dropbox or other file hosting services and just send us the download link.