Wix Installer detecting SELFFOUND when should be PREVIOUSFOUND - wix

Question

I have a strange issue whereby WiX Installer appears to be detecting a SELFFOUND instead of a PREVIOUSFOUND.
I am moving an old InstallAware project over to WiX so I have copied the UpgradeCode from the project to this Product.wxs
<Upgrade Id='MyGuid'>
<UpgradeVersion OnlyDetect='yes' Property='SELFFOUND' Minimum='!(bind.FileVersion.MainEXE)' IncludeMinimum='yes' Maximum='!(bind.FileVersion.MainEXE)' IncludeMaximum='yes' />
<UpgradeVersion OnlyDetect='yes' Property='NEWERFOUND' Minimum='!(bind.FileVersion.MainEXE)' IncludeMinimum='no' />
<UpgradeVersion Minimum="1.0.0"
IncludeMinimum="yes"
OnlyDetect="no"
Maximum="!(bind.FileVersion.MainEXE)"
IncludeMaximum="no"
Property="PREVIOUSFOUND" />
</Upgrade>
<CustomAction Id='AlreadyUpdated' Error='[ProductName] is already installed.' />
<CustomAction Id='NoDowngrade' Error='A later version of [ProductName] is already installed.' />
<InstallExecuteSequence>
<RemoveExistingProducts After="InstallInitialize"/>
<Custom Action='AlreadyUpdated' After='FindRelatedProducts'>SELFFOUND</Custom>
<Custom Action='NoDowngrade' After='FindRelatedProducts'>NEWERFOUND</Custom>
</InstallExecuteSequence>
and the Upgrade GUID matches that in my Product tag of the UpgradeCode attribute. The product codes between the two versions is different but I don't think making these the same is a good idea.
The version installed by the old InstallAware project is 4.11.7311.0 and is visible in control panel with this version. The version I am trying to install via the Upgrade and remove the old version is 4.11.7314.0.
For some reason whenever I try to run the new WiX .msi it is throwing the [ProductName] is already installed message.
Am I missing something? Because everything seems correct to me. Thanks in advance. Wix Toolset v3.11.

Answer 1

Okay, so I found the problem, well there were multiple actually.
Firstly I ran the installer via command prompt to generate a log file.
msiexec /i "C:\Path\To\Installer.msi" /L*V "C:\ProgramData\Install.log"
I then searched this file for
FindRelatedProducts
and it found an application which was setting the SELFFOUND property, now I searched through the registry for the GUID and realised it was an old one from my testing, so I uninstalled this using
msiexec /x {FoundGuid}
Still having the issue at this point though, so repeated the process and found a message that said
FindRelatedProducts: current install is per-machine. Related install for product '{MyGUID}' is per-user. Skipping...
so all I had to do was change my InstallScope from perMachine to perUser and it detects correctly.