Windows 3.1 Installer reinstalls old version right after uninstalling it rather than installing new upgrade

I have a MSI assembly which is an upgrade. The Upgradecode remains the same between the previous release and the new upgrade assembly. I also have the RemovePrevious attribute set so old version is removed before upgrade is installed.

I see the uninstallation of the old version occur as expected. However, the Windows Installer 3.1 immediately turns around are attempts to re-install the old开发者_JS百科 version again before it even proceeds to the new version. I have verified this by changing the first custom installation dialog in the newer version and see it just fine on a first install of the new version. But the dialog seen when upgrading is the old one which shipped with the previous release. I even rebuilt the old release with message box displays to verify that Installer is indeed re-installing the old version right after the uninstall rather than moving on to the new upgrade version.

Using MSIExec does not reveal any errors being logged to explain this odd behaviour and I cannot find any documentation that helps to identify why this is occurring.

Anyone have any ideas on why this behaviour is happening and how to go about fixing it?

Try increasing the version number of your app/dll in the embedded resources. The "new" behavior of the installer will not upgrade any exe/dlls unless the file versions have been bumped up.