diff --git a/scripts/diagnostics/Capture-MclCache.ps1 b/scripts/diagnostics/Capture-MclCache.ps1
index 4f8ff33..5ed38f7 100644
--- a/scripts/diagnostics/Capture-MclCache.ps1
+++ b/scripts/diagnostics/Capture-MclCache.ps1
@@ -189,8 +189,8 @@ Write-Host "Copying to $target ..."
 & robocopy.exe $dest $target /E /COPY:DT /R:2 /W:5 /NP /NFL /NDL /NJH /NJS | Out-Null
 $rc = $LASTEXITCODE
 if ($rc -ge 8) {
-    Write-Host "Copy FAILED (robocopy exit $rc)." -ForegroundColor Red
-    exit 2
+    # Keep going: the check below names the files that did not arrive.
+    Write-Host "robocopy could not copy some files (exit $rc)." -ForegroundColor Yellow
 }
 
 # Read every file back through the share and compare with SHA256SUMS.
@@ -200,16 +200,20 @@ foreach ($line in $sumLines) {
     $rel = $line.Substring(66)
     $copy = Join-Path $target ($rel.Replace('/', '\'))
     if (-not (Test-Path -LiteralPath $copy -PathType Leaf)) { $bad.Add("missing  $rel"); continue }
-    $got = (Get-FileHash -LiteralPath $copy -Algorithm SHA256).Hash.ToLower()
+    try { $got = (Get-FileHash -LiteralPath $copy -Algorithm SHA256).Hash.ToLower() }
+    catch { $bad.Add("unreadable  $rel"); continue }
     if ($got -ne $hash) { $bad.Add("differs  $rel ($((Get-Item -LiteralPath $copy).Length) bytes)") }
 }
-if ((Get-FileHash -LiteralPath (Join-Path $target "SHA256SUMS") -Algorithm SHA256).Hash -ne
-    (Get-FileHash -LiteralPath (Join-Path $dest "SHA256SUMS") -Algorithm SHA256).Hash) {
-    $bad.Add("differs  SHA256SUMS")
-}
+try {
+    if ((Get-FileHash -LiteralPath (Join-Path $target "SHA256SUMS") -Algorithm SHA256).Hash -ne
+        (Get-FileHash -LiteralPath (Join-Path $dest "SHA256SUMS") -Algorithm SHA256).Hash) {
+        $bad.Add("differs  SHA256SUMS")
+    }
+} catch { $bad.Add("unreadable  SHA256SUMS") }
 if ($bad.Count) {
     Write-Host "Copy NOT verified: $($bad.Count) of $($sumLines.Count + 1) files wrong." -ForegroundColor Red
     foreach ($b in $bad) { Write-Host "  $b" }
+    Write-Host "A file that arrives with 0 bytes was most likely blocked by this PC's policy."
     exit 2
 }
 Write-Host "Copied and verified: all $($sumLines.Count + 1) files match." -ForegroundColor Green