Minor error from me - the .msi file is called "WinAGI.installer.msi" but setup.exe is looking for "WinAGI Installer.msi".
I can change that to eliminate the space, which I just noticed is being converted to a '.' when the file is uploaded to github.
Slightly bigger error - when opening a previous .wag file it updates the logic files and places those in a backup folder, but copying those files back into the src folder is giving me a "invalid or corrupt game property file (AGI.wag)" in WinAGI 2.3.7.
This is by design; updating to WinAGI v3 changes the WAG file, and v3 game projects are not directly compatible with v2 game projects. The change is minimal, mostly adding and subtracting several different parameters. If you want to change it back to a version 2 project, you will need to edit the WAG file with a text editor, and change the "WinAGIVersion" property in the [General] section from 3.0 back to 2.3. Your WAG file may have some extraneous entries that version 2.3 won't use, but they can be safely ignored and the project should then open in version 2.3 again.