diff --git a/playbook/shopfloor-setup/Standard/Restore-UDCData.ps1 b/playbook/shopfloor-setup/Standard/Restore-UDCData.ps1
index 4ce4a5c..ace258e 100644
--- a/playbook/shopfloor-setup/Standard/Restore-UDCData.ps1
+++ b/playbook/shopfloor-setup/Standard/Restore-UDCData.ps1
@@ -6,7 +6,7 @@
 # whether there's actually any work to do.
 #
 # CONTRACT:
-#   - 99% of cycles: no backup waiting -> exit 0 in ~1 second, no side effects
+#   - 99% of cycles: no backup waiting -> exit 0 in ~1 second, ~5 lines of log
 #   - 1 cycle (the one after Backup-UDCData lands a backup for this PC's bay):
 #     stop UDC, copy CurrentData.json + ArchivedData/ to C:\ProgramData\UDC,
 #     move consumed backup to <bay>\migrated\<timestamp>\, write
@@ -25,6 +25,12 @@
 # the backup existed). Update-MachineNumber.ps1's branch still handles the
 # secondary case (tech used 9999 placeholder + sets number at bay) - both
 # triggers safely no-op if the other already consumed the backup.
+#
+# LOGGING:
+#   Single rotating log at C:\Logs\UDC\Restore-UDCData.log (1 MB cap, rotated
+#   to .old.log on overflow). Every cycle writes a header line so even the
+#   silent no-op path leaves a trace. Errors include full exception type,
+#   position, and stack trace.
 
 [CmdletBinding()]
 param(
@@ -32,160 +38,274 @@ param(
     [string]$UdcDataDir      = 'C:\ProgramData\UDC',
     [string]$UdcExePath      = 'C:\Program Files\UDC\UDC.exe',
     [string]$UdcSettingsPath = 'C:\ProgramData\UDC\udc_settings.json',
-    [string]$Site            = 'West Jefferson'
+    [string]$Site            = 'West Jefferson',
+    # Share can take 20-60s to become reachable from SYSTEM context after a
+    # cold boot or fresh logon. Retry until then before deciding "no backup".
+    [int]$ShareTimeoutSec    = 60,
+    [int]$SharePollSec       = 3
 )
 
-$ErrorActionPreference = 'Stop'
+$ErrorActionPreference = 'Continue'
+
+# -- Logging setup --------------------------------------------------------
 $logDir = 'C:\Logs\UDC'
-if (-not (Test-Path $logDir)) {
-    try { New-Item -Path $logDir -ItemType Directory -Force | Out-Null } catch { $logDir = $env:TEMP }
-}
-$logFile = Join-Path $logDir 'Restore-UDCData.log'
+try {
+    if (-not (Test-Path $logDir)) { New-Item -Path $logDir -ItemType Directory -Force | Out-Null }
+} catch { $logDir = $env:TEMP }
+$logFile        = Join-Path $logDir 'Restore-UDCData.log'
+$logFileMaxBytes = 1MB
+
+# Rotate log file if oversized (keeps one prior generation)
+try {
+    if ((Test-Path $logFile) -and ((Get-Item $logFile).Length -gt $logFileMaxBytes)) {
+        $rotated = Join-Path $logDir 'Restore-UDCData.old.log'
+        if (Test-Path $rotated) { Remove-Item $rotated -Force -ErrorAction SilentlyContinue }
+        Rename-Item -Path $logFile -NewName 'Restore-UDCData.old.log' -Force -ErrorAction SilentlyContinue
+    }
+} catch {}
 
 function Log {
     param([string]$Msg, [string]$Level = 'INFO')
-    $ts = Get-Date -Format 'yyyy-MM-dd HH:mm:ss'
+    $ts = Get-Date -Format 'yyyy-MM-dd HH:mm:ss.fff'
     $line = "[$ts][$Level] $Msg"
-    Add-Content -LiteralPath $logFile -Value $line
+    try { Add-Content -LiteralPath $logFile -Value $line -ErrorAction SilentlyContinue } catch {}
     Write-Host $line
 }
 
-# --- Resolve local machine number ---
+function LogErr {
+    param($Err)
+    if (-not $Err) { return }
+    $exType = if ($Err.Exception) { $Err.Exception.GetType().FullName } else { '<no exception>' }
+    $exMsg  = if ($Err.Exception) { $Err.Exception.Message } else { "$Err" }
+    Log "  exception: $exType - $exMsg" 'ERROR'
+    if ($Err.InvocationInfo -and $Err.InvocationInfo.PositionMessage) {
+        $pos = ($Err.InvocationInfo.PositionMessage -replace "`r?`n", ' | ')
+        Log "  at: $pos" 'ERROR'
+    }
+    if ($Err.ScriptStackTrace) {
+        $st = ($Err.ScriptStackTrace -replace "`r?`n", ' | ')
+        Log "  stack: $st" 'ERROR'
+    }
+    if ($Err.Exception -and $Err.Exception.InnerException) {
+        Log "  inner: $($Err.Exception.InnerException.Message)" 'ERROR'
+    }
+}
+
+Log '==============================================='
+Log "Restore-UDCData starting (PID $PID)"
+Log "Hostname:           $env:COMPUTERNAME"
+try {
+    $whoami = [System.Security.Principal.WindowsIdentity]::GetCurrent().Name
+} catch { $whoami = '<unknown>' }
+Log "User identity:      $whoami"
+Log "PowerShell version: $($PSVersionTable.PSVersion)"
+Log "BackupShareRoot:    $BackupShareRoot"
+Log "UdcDataDir:         $UdcDataDir"
+Log "UdcSettingsPath:    $UdcSettingsPath"
+Log "ShareTimeoutSec:    $ShareTimeoutSec   SharePollSec: $SharePollSec"
+
+# -- Resolve local machine number ----------------------------------------
 if (-not (Test-Path -LiteralPath $UdcSettingsPath)) {
-    # No UDC installed yet. Manifest engine will catch up later if/when it lands.
+    Log "udc_settings.json not present - UDC not installed yet, no work to do."
+    Log 'Exit 0.'
     exit 0
 }
 try {
-    $json = Get-Content -LiteralPath $UdcSettingsPath -Raw | ConvertFrom-Json
+    $json = Get-Content -LiteralPath $UdcSettingsPath -Raw -ErrorAction Stop | ConvertFrom-Json -ErrorAction Stop
     $mn = $json.GeneralSettings.MachineNumber
+    Log "Resolved MachineNumber from udc_settings: $mn"
 } catch {
-    Log "Failed to parse $UdcSettingsPath : $_" 'ERROR'
+    Log "Failed to parse $UdcSettingsPath" 'ERROR'
+    LogErr $_
+    Log 'Exit 0.'
     exit 0
 }
 if (-not $mn -or $mn -eq '9999' -or $mn -notmatch '^\d+$') {
-    # Placeholder or invalid - the placeholder->real trigger in
-    # Update-MachineNumber.ps1 will catch it when the tech sets a real number.
+    Log "Machine number is placeholder/empty/non-numeric ('$mn'). Update-MachineNumber.ps1's branch will catch the placeholder->real transition. No work to do."
+    Log 'Exit 0.'
     exit 0
 }
 
-# --- Probe for a waiting backup ---
+# -- Wait for the share to be reachable ---------------------------------
+# When this script runs early in a logon (e.g. via GE-Enforce on autologon),
+# the SFLD share via the SMB redirector can take 20-60 seconds to become
+# reachable, especially in SYSTEM context where the credential is the
+# computer account. Poll until reachable or timeout before deciding "no backup".
+Log "Polling share root for reachability: $BackupShareRoot"
+$shareReachable = $false
+$sw = [Diagnostics.Stopwatch]::StartNew()
+while ($sw.Elapsed.TotalSeconds -lt $ShareTimeoutSec) {
+    if (Test-Path -LiteralPath $BackupShareRoot) {
+        $shareReachable = $true
+        break
+    }
+    Start-Sleep -Seconds $SharePollSec
+}
+$sw.Stop()
+if ($shareReachable) {
+    Log ("Share reachable after {0:N1} s" -f $sw.Elapsed.TotalSeconds)
+} else {
+    Log "Share NOT reachable after $ShareTimeoutSec s. Cannot probe for backup. Exiting non-zero so the dispatcher logs a failure." 'ERROR'
+    Log 'Exit 1.'
+    exit 1
+}
+
+# -- Probe for a waiting backup ------------------------------------------
 $bayDir = Join-Path $BackupShareRoot $mn
 $srcCur = Join-Path $bayDir 'CurrentData.json'
 $srcArc = Join-Path $bayDir 'ArchivedData'
+Log "Probing backup paths for bay $mn"
+Log "  bayDir: $bayDir"
+$bayDirExists = Test-Path -LiteralPath $bayDir
+Log "  bayDir exists:        $bayDirExists"
+$srcCurExists = Test-Path -LiteralPath $srcCur
+Log "  CurrentData.json src: $(if ($srcCurExists) { 'present' } else { 'absent' }) - $srcCur"
+$srcArcExists = Test-Path -LiteralPath $srcArc
+Log "  ArchivedData/ src:    $(if ($srcArcExists) { 'present' } else { 'absent' }) - $srcArc"
 
-if (-not (Test-Path -LiteralPath $srcCur)) {
-    # Most-common path: no backup waiting. Exit silently to keep enforce-cycle
-    # logs clean. (Manifest engine still records that the entry ran.)
+if (-not $srcCurExists) {
+    Log "No backup waiting for bay $mn - no work to do this cycle."
+    Log 'Exit 0.'
     exit 0
 }
 
-# We have a backup. From here on, log everything.
-Log "==============================================="
-Log "UDC data backup detected at $bayDir - restoring."
-Log "Hostname:       $env:COMPUTERNAME"
-Log "Machine number: $mn"
+# -- We have a backup. Restore. ------------------------------------------
+Log "Backup waiting at $bayDir - proceeding with restore"
 
-# --- Stop UDC.exe so CurrentData.json isn't locked ---
-Get-Process UDC -ErrorAction SilentlyContinue | ForEach-Object {
+# Stop UDC.exe so CurrentData.json isn't locked
+$udcProcs = @(Get-Process UDC -ErrorAction SilentlyContinue)
+Log "UDC processes currently running: $($udcProcs.Count)"
+foreach ($p in $udcProcs) {
     try {
-        $_.Kill()
-        $_.WaitForExit(5000) | Out-Null
-        Log "Stopped existing UDC.exe (PID $($_.Id))"
+        Log "  stopping UDC.exe PID $($p.Id)"
+        $p.Kill()
+        $p.WaitForExit(5000) | Out-Null
+        Log "    stopped"
     } catch {
-        Log "Could not stop UDC.exe (PID $($_.Id)): $_" 'WARN'
+        Log "    could not stop UDC.exe PID $($p.Id)" 'WARN'
+        LogErr $_
     }
 }
 Start-Sleep -Milliseconds 500
 
-# --- Ensure local UDC data dir exists ---
+# Ensure local UDC data dir exists
 if (-not (Test-Path -LiteralPath $UdcDataDir)) {
-    New-Item -ItemType Directory -Path $UdcDataDir -Force | Out-Null
+    Log "Creating local UDC data dir: $UdcDataDir"
+    try {
+        New-Item -Path $UdcDataDir -ItemType Directory -Force | Out-Null
+    } catch {
+        Log "Failed to create $UdcDataDir - cannot continue" 'ERROR'
+        LogErr $_
+        Log 'Exit 1.'
+        exit 1
+    }
 }
 $localCur = Join-Path $UdcDataDir 'CurrentData.json'
 $localArc = Join-Path $UdcDataDir 'ArchivedData'
 
-# --- Copy CurrentData.json ---
+# Copy CurrentData.json
 $copiedCur = $false
+Log "Copying CurrentData.json"
+Log "  src: $srcCur"
+Log "  dst: $localCur"
 try {
     Copy-Item -LiteralPath $srcCur -Destination $localCur -Force -ErrorAction Stop
     $copiedCur = $true
-    Log "Copied CurrentData.json ($((Get-Item $localCur).Length) bytes)"
+    $sz = (Get-Item -LiteralPath $localCur).Length
+    Log "  OK ($sz bytes)"
 } catch {
-    Log "Copy CurrentData.json failed: $_" 'ERROR'
+    Log "  FAILED" 'ERROR'
+    LogErr $_
 }
 
-# --- Copy ArchivedData/ ---
+# Copy ArchivedData/
 $copiedArc = $false
 $arcFiles  = 0
 $arcBytes  = 0
-if (Test-Path -LiteralPath $srcArc) {
+if ($srcArcExists) {
+    Log "Copying ArchivedData/"
+    Log "  src: $srcArc"
+    Log "  dst: $localArc"
     try {
         if (Test-Path -LiteralPath $localArc) {
+            Log "  removing existing $localArc"
             Remove-Item -LiteralPath $localArc -Recurse -Force -ErrorAction SilentlyContinue
         }
         Copy-Item -LiteralPath $srcArc -Destination $localArc -Recurse -Force -ErrorAction Stop
         $arcItems = Get-ChildItem -LiteralPath $localArc -Recurse -File -ErrorAction SilentlyContinue
-        $arcFiles = $arcItems.Count
+        $arcFiles = @($arcItems).Count
         $arcBytes = ($arcItems | Measure-Object Length -Sum).Sum
         $copiedArc = $true
-        Log "Copied ArchivedData/ ($arcFiles files, $arcBytes bytes)"
+        Log "  OK ($arcFiles files, $arcBytes bytes)"
     } catch {
-        Log "Copy ArchivedData/ failed: $_" 'ERROR'
+        Log "  FAILED" 'ERROR'
+        LogErr $_
     }
+} else {
+    Log "ArchivedData/ not present in backup - skipping that copy step"
 }
 
-# --- One-shot consumption: only move backup -> migrated/ if BOTH copies succeeded ---
-# (If one failed, leave the live backup in place so the next cycle can retry.)
-$consumeOk = ($copiedCur -and ($copiedArc -or -not (Test-Path -LiteralPath $srcArc)))
+# One-shot consumption: only move backup -> migrated/ if everything required succeeded
+$consumeOk = ($copiedCur -and ($copiedArc -or -not $srcArcExists))
+Log "consumeOk=$consumeOk (copiedCur=$copiedCur, copiedArc=$copiedArc, srcArcExists=$srcArcExists)"
+
 if ($consumeOk) {
     try {
         $stamp    = Get-Date -Format 'yyyy-MM-ddTHH-mm-ssZ'
         $migDir   = Join-Path $bayDir 'migrated'
         $migStamp = Join-Path $migDir $stamp
+        Log "Moving consumed backup to $migStamp"
         if (-not (Test-Path -LiteralPath $migDir))   { New-Item -ItemType Directory -Path $migDir   -Force | Out-Null }
         if (-not (Test-Path -LiteralPath $migStamp)) { New-Item -ItemType Directory -Path $migStamp -Force | Out-Null }
 
         Move-Item -LiteralPath $srcCur -Destination (Join-Path $migStamp 'CurrentData.json') -Force -ErrorAction Stop
+        Log "  moved CurrentData.json"
         if (Test-Path -LiteralPath $srcArc) {
             Move-Item -LiteralPath $srcArc -Destination (Join-Path $migStamp 'ArchivedData') -Force -ErrorAction Stop
+            Log "  moved ArchivedData/"
         }
         $bakManifest = Join-Path $bayDir 'backup.manifest.json'
         if (Test-Path -LiteralPath $bakManifest) {
             Move-Item -LiteralPath $bakManifest -Destination (Join-Path $migStamp 'backup.manifest.json') -Force -ErrorAction SilentlyContinue
+            Log "  moved backup.manifest.json"
         }
 
         $restoreManifest = [ordered]@{
             RestoredAt          = (Get-Date -Format 'o')
             DestinationHostname = $env:COMPUTERNAME
-            DestinationUser     = [System.Security.Principal.WindowsIdentity]::GetCurrent().Name
+            DestinationUser     = $whoami
             MachineNumber       = $mn
-            CurrentDataBytes    = (Get-Item $localCur).Length
-            ArchivedDataFiles    = $arcFiles
-            ArchivedDataBytes    = $arcBytes
+            CurrentDataBytes    = (Get-Item -LiteralPath $localCur).Length
+            ArchivedDataFiles   = $arcFiles
+            ArchivedDataBytes   = $arcBytes
             RestoredVia         = 'Restore-UDCData.ps1 (manifest engine, on logon)'
         }
         $restoreManifest | ConvertTo-Json | Set-Content -Path (Join-Path $migStamp 'restore.manifest.json') -Encoding UTF8
+        Log "  wrote restore.manifest.json"
 
         Log "Backup consumed -> migrated\$stamp\"
     } catch {
-        Log "Move-to-migrated failed (data IS restored locally, but live backup remains - next cycle will retry consumption): $_" 'ERROR'
+        Log "Move-to-migrated FAILED (data IS restored locally; live backup remains, next cycle will retry consumption)" 'ERROR'
+        LogErr $_
     }
 } else {
     Log "Restore incomplete - leaving live backup at $bayDir for retry next cycle." 'WARN'
 }
 
-# --- Relaunch UDC with the current machine number args so it picks up the
-#     restored CurrentData.json. UDC's vendor autostart in HKLM\Run will also
-#     fire on the next user logon, so this is belt-and-suspenders for the
-#     same-session case (e.g. tech is at the keyboard during the restore). ---
+# Relaunch UDC with the current machine number args. UDC's vendor autostart in
+# HKLM\Run will also fire on the next user logon, so this is belt-and-suspenders
+# for the same-session case (e.g. tech is at the keyboard during the restore).
 if ((Test-Path -LiteralPath $UdcExePath) -and $copiedCur) {
+    Log "Relaunching UDC.exe: `"$Site`" -$mn"
     try {
         Start-Process -FilePath $UdcExePath -ArgumentList @("`"$Site`"", "-$mn")
-        Log "Relaunched UDC.exe with `"$Site`" -$mn"
+        Log "  relaunched"
     } catch {
-        Log "UDC relaunch failed: $_" 'WARN'
+        Log "  UDC relaunch FAILED" 'WARN'
+        LogErr $_
     }
 }
 
-Log "==============================================="
+Log 'Exit 0.'
+Log '==============================================='
 exit 0