Root cause of fleet not reporting: long-running entries (UDC's
WaitTimeoutSec=120) keep the dispatcher CPU-busy with no SMB traffic
to W:. SMB server times out the idle session. W: stays as a "mapped"
drive letter on the client but Path operations against it fail with
weird errors (e.g. "Cannot bind argument to parameter 'Path' because
it is null" via downstream Join-Path / Test-Path null cascades).
Fix:
- Re-attach W: at the top of the status write-back block (cheap; if
still alive net use returns 'already mapped'; if dead, freshly
remounts).
- Null-guard $hostname (fall back to 'UNKNOWN') and explicitly throw
if $driveLetter is unset (catch surfaces a clear error in log).
- Pair with UDC manifest WaitTimeoutSec reduction 120 -> 60 on the v2
share to limit how long the SMB stays idle in the first place.
Surfaced via blah*.txt log captures from 3 deployed bays (3105, 3115,
3116, 3118 era) - all showed "Status write-back failed: Cannot bind
argument to parameter 'Path' because it is null" while everything
upstream (manifest entries) ran clean.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>