Thanks, we spoke today.  The work around was simply to install in a new folder as I've got a 2TB disc that's not going to be a problem anytime soon.  What the cause is GAK!

Thanks Tim,
Cracked that now thanks - I found the update had moved all my files from "Documents" under C into a f‌‌older under  User/ but left the SD files behind and then the download created new empty SD files in the new location.  Love Microsoft...........
John‌

Those files are simply documents under My Documents\SkyDemon. If you copy them across, SkyDemon will recognise them.

Further to Windows 10 updates.  An automatic update trashed the location of most of my laptop files but they are all still on the machine.  I reloaded Skydemon as the application had gone and I have found my original Skydemon data files but the new application does not recognise them.  Is there a way to import my old aircraft and track files into the new application?

John‌‌

Contact our support.

When trying to install the latest update I received an error message that an existing file could not be renamed.  I tried uninstalling Skydemon before re-installing but the uninstall also failed.  The system will now not allow me to delete the existing Skydemon directory.  So I'm now stuck without Skydemon on my computer.  If I had the option of placing it in a different file location that might help but it doesn't give that on installation.  How do I sort this out.