X_STORAGE_SCAN_UNAVAILABLE
Means
the upload scanner could not give a verdict
Typical cause
the uploadScanner installed in runtime.ts rejected (daemon down, timeout, file past its limit), or the per-attempt copy could not be read for it, and the upload policy fails closed; the attempt copy is deleted and the upload stays pending
Fix
promoteAttachment({ disk, key, orgId, target, policy }) # again once the scanner answers — or uploadPolicy({ onScanUnavailable: 'accept' }) to promote unscanned files