Adding Merge Module to Wix Project Causes Upgrade to Fail - installation

Question

So, I have a product installer authored using WiX which is failing to upgrade correctly once the 'Microsoft_VC100_CRT_x86.msm' merge module is incorporated. The old product is not removed during the installation. If the merge modules are removed from the project the removal of the old version takes place as it should.
The merge module is included quite simply under a Directory node:
<Directory Id="ProgramFilesFolder">
<Merge Id="VC10_CRT_MergeId1" Language="0" SourceFile="c:\\Program Files (x86)\\Common Files\\Merge Modules\\Microsoft_VC100_CRT_x86.msm" DiskId="1" />
... other stuff
</Directory>
and then referenced in the features:
<Feature Id="MainFeature" Title="Core Files" Level="1">
<MergeRef Id="VC10_CRT_MergeId1" />
... other stuff
</Feature>
I am incrementing the version number of the product but the upgrade fails to happen and the new version is installed over the old version but without performing a correct upgrade - both versions are listed in 'Add or Remove Programs'.
The old product should be removed as follows:
<InstallExecuteSequence>
<RemoveExistingProducts After='InstallValidate'/>
</InstallExecuteSequence>
I have also tried various other positions for RemoveExistingProducts as per http://jpassing.com/2007/06/16/where-to-place-removeexistingproducts-in-a-major-msi-upgrade/, with the same results.
In the verbose log for the installer the following is seen:
MSI (s) (AC:44) [19:48:22:300]: Doing action: RemoveExistingProducts
MSI (s) (AC:44) [19:48:22:300]: Note: 1: 2205 2: 3: ActionText
Action start 19:48:22: RemoveExistingProducts.
MSI (s) (AC:44) [19:48:22:300]: Note: 1: 2205 2: 3: Error
MSI (s) (AC:44) [19:48:22:300]: Note: 1: 2228 2: 3: Error 4: SELECT `Message` FROM `Error` WHERE `Error` = 22
MSI (s) (AC:44) [19:48:22:301]: Note: 1: 2205 2: 3: Error
MSI (s) (AC:44) [19:48:22:301]: Note: 1: 2228 2: 3: Error 4: SELECT `Message` FROM `Error` WHERE `Error` = 23
MSI (s) (AC:44) [19:48:22:301]: Note: 1: 2205 2: 3: Error
MSI (s) (AC:44) [19:48:22:301]: Note: 1: 2228 2: 3: Error 4: SELECT `Message` FROM `Error` WHERE `Error` = 16
MSI (s) (AC:44) [19:48:22:301]: Note: 1: 2205 2: 3: Error
MSI (s) (AC:44) [19:48:22:301]: Note: 1: 2228 2: 3: Error 4: SELECT `Message` FROM `Error` WHERE `Error` = 21
Action ended 19:48:22: RemoveExistingProducts. Return value 1.
In the WiX build log I get the following (but from memory this is normal with the VC runtime msms?):
1>light.exe(0,0): warning LGHT1076: ICE82: This action SystemFolder_x86_VC.F1DD796A_B984_3DCA_A68D_6B352BDC86F3 has duplicate sequence number 1 in the table InstallExecuteSequence
1>light.exe(0,0): warning LGHT1076: ICE82: This action SystemFolder_x86_VC.F1DD796A_B984_3DCA_A68D_6B352BDC86F3 has duplicate sequence number 1 in the table InstallUISequence
1>light.exe(0,0): warning LGHT1076: ICE82: This action SystemFolder_x86_VC.F1DD796A_B984_3DCA_A68D_6B352BDC86F3 has duplicate sequence number 3 in the table AdminExecuteSequence
1>light.exe(0,0): warning LGHT1076: ICE82: This action SystemFolder_x86_VC.F1DD796A_B984_3DCA_A68D_6B352BDC86F3 has duplicate sequence number 3 in the table AdminUISequence
1>light.exe(0,0): warning LGHT1076: ICE82: This action SystemFolder_x86_VC.F1DD796A_B984_3DCA_A68D_6B352BDC86F3 has duplicate sequence number 3 in the table AdvtExecuteSequence
The InstallExecuteSequence in the msi looks like the following:
If the merge module is removed (it needs to be included due to updated files in the installer) then the upgrade works as expected. Is this a bug in the merge module stuff/WiX/Windows Installer, or am I doing something wrong?

Answer 1

You're not getting any error messages on the upgrade? It goes through but you're left with two Add/Remove entries and a messed up file system? It sounds like your two versions don't share the same upgrade code.
If you're trying to do a minor upgrade, RemoveExistingProducts won't be triggered. Files should be updated but you'll keep one Add/Remove entry.
If you're trying to do a major upgrade that will trigger RemoveExistingProducts, but you need to set up the Upgrade element correctly.
Also, as a tip, don't use the merge modules. Due to how Windows Installer component rules work, on a minor upgrade you cannot remove the components the merge module adds. You would need to introduce a major upgrade. (Or add all the component codes from the old merge module to your project by hand. Not fun.) Depending on how all your stuff is set up, forcing a major upgrade could be a big hassle.
You'll run into this if you add the merge module and later need to remove it. Or if you want to replace say the VS 2010 module with the VS 2012 one. MS even broke component rules between service packs once. It's much easier to install them by running the vcredist*.exes during or before your product's install.

Answer 2

Have you found the problem yet? Check if the version of merge modules you are adding is older than that already existing on the system you are installing. In that case, the MSI would remove the VC++ files but not put the new ones down because they were older.
Edit: I found the solution to your problem!!
you should be using:
RemoveExistingProducts After="InstallFinalize
Refer: http://blogs.msdn.com/b/astebner/archive/2007/02/08/assemblies-may-be-missing-from-the-gac-or-winsxs-cache-after-an-msi-major-upgrade.aspx
I had the same issue and changing this fixed it.