Play assets not ready

The scene references assets that are not imported yet or failed to import, so the player cannot load them.

#Common causes

• An import is still running for a referenced asset.
• An import failed (see the related ARA21xx asset diagnostic).
• A referenced asset's source is missing.

#Fixes

• Wait for jobs to finish, then press Play again.

• Fix the failing import named in the message and re-import it.

• Point the referencing field at an asset that exists (property.set).

• Code: ARA7303

• Constant: play::ASSETS

• Reported by: ara-play-host