diff --git a/certy.ps1 b/certy.ps1
index 7696fad..6beae28 100644
--- a/certy.ps1
+++ b/certy.ps1
@@ -892,7 +892,7 @@ $csrImportBtn.Add_Click({
             return
         }
 
-        $csrHosts = $csrFiles | ForEach-Object { $_.BaseName.Trim() } | Where-Object { $_ }
+        $csrHosts = @($csrFiles | ForEach-Object { $_.BaseName.Trim() } | Where-Object { $_ })
         $currentHosts = Split-List $hostsBox.Text
         $merged = Merge-Hostnames -Existing $currentHosts -NewItems $csrHosts
         $hostsBox.Text = ($merged -join [Environment]::NewLine)
@@ -905,7 +905,7 @@ $csrImportBtn.Add_Click({
 $dnsScanBtn.Add_Click({
     try {
         $dnsListBox.Items.Clear()
-        $servers = Get-DnsServerCandidates
+        $servers = @(Get-DnsServerCandidates)
         if (-not $servers -or $servers.Count -eq 0) {
             & $logAction "No DNS servers found. Enter servers manually."
             return
@@ -1025,7 +1025,7 @@ $runBtn.Add_Click({
             throw "PFX password is required."
         }
 
-        $hostEntries = $hosts | ForEach-Object { Resolve-HostEntry -Name $_ -Zone $zone -UseProvidedFqdn $useFqdnBox.Checked } | Where-Object { $_ }
+        $hostEntries = @($hosts | ForEach-Object { Resolve-HostEntry -Name $_ -Zone $zone -UseProvidedFqdn $useFqdnBox.Checked } | Where-Object { $_ })
 
         & $logAction "Processing $($hostEntries.Count) hostname(s)."
 
@@ -1037,7 +1037,7 @@ $runBtn.Add_Click({
             if ($selectedReplicationTargets.Count -gt 0) {
                 $replicationTargets = $selectedReplicationTargets
             } else {
-                $replicationTargets = Split-List $replicationTargetsBox.Text
+                $replicationTargets = @(Split-List $replicationTargetsBox.Text)
                 if ($replicationTargets.Count -eq 0 -and $dnsServer) {
                     $replicationTargets = @($dnsServer)
                     & $logAction "Replication targets empty; using primary DNS server $dnsServer."
@@ -1071,7 +1071,7 @@ $runBtn.Add_Click({
                         -Log $logAction
                 }
             } else {
-                $hostList = $hostEntries | ForEach-Object { $_.Fqdn }
+            $hostList = @($hostEntries | ForEach-Object { $_.Fqdn } | Where-Object { $_ })
                 & $logAction "Requesting one certificate with $($hostList.Count) hostname(s)."
                 Invoke-Wacs `
                     -WacsPath $wacsPath `