This asset uses an obsolete trainz-build number. Trainz-build numbers below #.# are no longer supported.
This asset has a "Trainz-build" number which is less than the current minimum supported build number. In short, it's an old asset which likely doesn't meet up to current standards for content creation. The asset can still be used in Trainz and should function as originally built, but likely lacks support for modern features and may use config.txt techniques which differ from current expectations.
N3V permits uploading such assets to the Download Station for the purposes of supporting legacy content. Such assets will be flagged for repair and upgrade. N3V Games does not permit uploading such assets as an update to an existing Download Station asset; the creator is required to upgrade the asset to a supported version before releasing it as an update.
Changing the trainz-build tag in config.txt to the current minimum supported build number (or higher) will eliminate this warning, but will also hold the rest of the asset to the appropriate more modern standards, which may in turn reveal additional items requiring upgrade.