Go to C:\Users\SomeName\AppData\Local\SCF Licenses and delete the following

SCFLicenseSignature - DO NOT MODIFY OR DELETE.txt

Close SketchUp

Start SketchUp

Now go to Tools > Fredo Collection > Fredoscale > License... and activate the license file using the file at https://sketchucation.com/webshop/my-licences.php

Also please run the Window > Libfredo Settings > Fredo6 Plugins Information for Sketchucation Support in SketchUp and copy/paste the info here please.