About #5, thank you for the screenshot. By reading the migration assistant batch script, the only reasons that could cause this message to print is if one of the builder's executables is not here (which would mean an incomplete installation), or a corrupted environment (especially the PATH and TEMP environment variables). Please reinstall the builder and see if this error happens again. If it does, you should check that these 2 session-wide environment variables point to existing directories.

:: @Pierre-Marie Baty added on 24 Nov ’23 · 14:49

*edit* if it went far too quickly, as you said, I'd bet that the unzip.exe tool is missing from the Toolchain directory. Which would mean a broken installation.