diff --git a/.gitea/workflows/build.yml b/.gitea/workflows/build.yml
index 0f69b97..d1eea3a 100644
--- a/.gitea/workflows/build.yml
+++ b/.gitea/workflows/build.yml
@@ -258,15 +258,21 @@ jobs:
               & msbuild @msbuildArgs
               if ($LASTEXITCODE -ne 0) { throw "msbuild /t:Publish failed with $LASTEXITCODE" }
 
-              # Sanity check: did the VSTO publish target produce a .vsto file?
-              $vsto = Get-ChildItem -Recurse -Filter '*.vsto' -Path publish | Select-Object -First 1
-              if (-not $vsto) { throw "msbuild /t:Publish completed but no .vsto file found under publish/" }
+              # Sanity check + rename to canonical OutlookAddin.vsto so the URL
+              # matches PROVIDER_URL (hardcoded to .../OutlookAddin.vsto). Restrict
+              # to publish/ root -- there's a second .vsto inside Application Files
+              # that must keep its versioned name. Verify the renamed file exists
+              # before continuing; v1.2.11 shipped broken because a silent failure
+              # here left no OutlookAddin.vsto in the tar and 404'd the CDN.
+              $vsto = Get-ChildItem -File -Filter '*.vsto' -Path publish | Select-Object -First 1
+              if (-not $vsto) { throw "msbuild /t:Publish completed but no .vsto file found at publish/ root" }
               Write-Host "  produced $($vsto.FullName)"
-
-              # Rename to canonical OutlookAddin.vsto so the ClickOnce manifest
-              # URL matches PROVIDER_URL (which is hardcoded to .../OutlookAddin.vsto).
               if ($vsto.Name -ne 'OutlookAddin.vsto') {
-                  Rename-Item -LiteralPath $vsto.FullName -NewName 'OutlookAddin.vsto'
+                  Rename-Item -LiteralPath $vsto.FullName -NewName 'OutlookAddin.vsto' -ErrorAction Stop
+                  Write-Host "  renamed -> OutlookAddin.vsto"
+              }
+              if (-not (Test-Path 'publish/OutlookAddin.vsto')) {
+                  throw "post-rename: publish/OutlookAddin.vsto does not exist"
               }
 
               Write-Host "=== STEP F: stage protocol handler ==="
diff --git a/src/OutlookAddin/Properties/AssemblyInfo.cs b/src/OutlookAddin/Properties/AssemblyInfo.cs
index 6346bc1..a8df476 100644
--- a/src/OutlookAddin/Properties/AssemblyInfo.cs
+++ b/src/OutlookAddin/Properties/AssemblyInfo.cs
@@ -33,6 +33,6 @@ using System.Security;
 // You can specify all the values or you can default the Build and Revision Numbers 
 // by using the '*' as shown below:
 // [assembly: AssemblyVersion("1.0.*")]
-[assembly: AssemblyVersion("1.2.11.0")]
-[assembly: AssemblyFileVersion("1.2.11.0")]
+[assembly: AssemblyVersion("1.2.12.0")]
+[assembly: AssemblyFileVersion("1.2.12.0")]