diff --git a/playbook/preinstall/opentext/Setup-OpenText.ps1 b/playbook/preinstall/opentext/Setup-OpenText.ps1
index 16abdf2..1dbd8f4 100644
--- a/playbook/preinstall/opentext/Setup-OpenText.ps1
+++ b/playbook/preinstall/opentext/Setup-OpenText.ps1
@@ -41,6 +41,16 @@ if (-not $SourceDir) {
     $SourceDir = $PSScriptRoot
 }
 
+# Normalize $SourceDir to a canonical absolute path. The CMD shim passes
+# "%~dp0..\apps\opentext" which embeds a literal "..". msiexec / the Windows
+# Installer service fail to open the package with that unresolved segment
+# (exit 1619, ERROR_INSTALL_PACKAGE_OPEN_FAILED), even though every other
+# .NET / PowerShell API resolves it fine. Resolve-Path collapses ".." into
+# a clean drive-rooted path before any msiexec invocation.
+if (Test-Path -LiteralPath $SourceDir) {
+    try { $SourceDir = (Resolve-Path -LiteralPath $SourceDir).ProviderPath } catch {}
+}
+
 # --- Inline site-config reader (this script runs from C:\PreInstall\installers\opentext\,
 # NOT from C:\Enrollment\shopfloor-setup\, so it can't dot-source Get-PCProfile.ps1) ---
 function Get-SiteConfig {