On-Demand Resources cannot re-download a changed pack.remove ends access and the system frees the space later, so the integrity retry on iOS 17 and 18 reads the same files and reports Failed(Corrupt). Apple-hosted packs and Play re-download.
Background Assets on iOS 26.4 and later: forum reports describe downloads failing or packs marked ready with files missing. The integrity check and the single retry cover the missing-file case.
Play local testing cannot simulate network errors, the Wi-Fi wait or pack updates. Use Play's internal app sharing for those.
PNG files in On-Demand Resources may be re-encoded by Xcode's COMPRESS_PNG_FILES on device builds, which changes their hash. Turn the setting off for targets with packs, or keep images in formats Xcode does not touch.
Play state() can, rarely, emit an older snapshot right after a newer update when the flow starts during a status change. The next update corrects it.
iOS error mapping does not yet follow NSUnderlyingErrorKey, so an offline Background Assets failure may surface as NotFound or Unknown.