Thank you for the detailed bug report on the icon file path issue.
Our team is investigating this issue and will provide an update as soon as we have more information. In the meantime, here are some helpful resources for validating your app manifest and understanding the manifest structure:
This has been fixed. The vpt pack command now validates that the icon file declared in manifest.toml exists before generating the .vpkg - if it’s missing, you’ll get a clear error at pack time instead of the cryptic install failure. This is available in the latest VPT release.