patch fails update files reports success

Summary:
I’m applying a patch (myapp.msp) to an application.
The patch works correctly if I right click on the msp file and select “apply.” However, when invoked programmatically, with elevated privileges, the UI reports success but no files are updated. To make matters worse, the application version number in control panel/installed programs is updated to the “new” version.
Detail:
Both the patch and the application were created with InstalledShiled Developer 8.0.
I’m applying the patch in 3 different ways: 1. Right click patch file and select “Apply” 2. With a batch file, invoked “as administrator”, containing “msiexec –p mypatch.msi” 3. From an application, with manifest that requires elevated privileges
From an end user point of view, all three methods result in invoking the patch process, and after some crunching it reports success.
However, only #1 updates the application correctly. #2 and #3 do not update any of the files, but they do update the application version number as appears in Control Panel / Installed Programs.
Examining the log files for method #1 vs. method #2 shows only one significant difference. The “pass” case shows MsiNetAssemblySupport= 2.0.50727.88. The “Fail” case shows MsiNetAssemblySupport= 2.0.50727.00.

Problem was caused by faulty patch. It is now resolved. Thank you!

Problem was caused by faulty patch. It is now resolved. Thank you!