WiX toolset - EventSource sets wrong path to EventMessageFile (prepends "#%")

Question

I have WiX 4.0 project. I'm using Util to create Windows EventLog event source. The problem is, the Registry entry to the EventMessageFile gets the path prepended with "#%". Therefore, the EventLog will display errors for events created by this event source.

Code to create the EventSource:

<Include xmlns="http://wixtoolset.org/schemas/v4/wxs" xmlns:util="http://wixtoolset.org/schemas/v4/wxs/util">
    <PropertyRef Id="NETFRAMEWORK40FULLINSTALLROOTDIR64"/>
    <PropertyRef Id="NETFRAMEWORK40CLIENTINSTALLROOTDIR64"/>
    <PropertyRef Id="NETFRAMEWORK40CLIENT"/>
    <PropertyRef Id="NETFRAMEWORK40FULL"/>

.
.
.

    <ComponentGroup Id="EventLog" Directory="INSTALLFOLDER">
        <!-- 64 bit -->
        <Component Id="CreateEventSource64BitFullNet4" DiskId="1" Guid="{9978592B-3E96-4AAA-B7A6-34B0421FDD02}" Condition="NETFRAMEWORK40FULLINSTALLROOTDIR64 AND VersionNT64">
            <CreateFolder/>
            <util:EventSource Log="Application" Name="ScholarshipSapQueue" EventMessageFile="[NETFRAMEWORK40FULLINSTALLROOTDIR64]EventLogMessages.dll" />
        </Component>
        <Component Id="CreateEventSource64BitClientNet4" DiskId="1" Guid="{B42622A1-B7C0-48CB-B306-65F3558C6678}" Condition="NETFRAMEWORK40CLIENTINSTALLROOTDIR64 AND NOT NETFRAMEWORK40FULL AND VersionNT64">
            <CreateFolder/>
            <util:EventSource Log="Application" Name="ScholarshipSapQueue" EventMessageFile="[NETFRAMEWORK40CLIENTINSTALLROOTDIR64]EventLogMessages.dll" />
        </Component>
    </ComponentGroup>
</Include>

Looking at the log file from installing the MSI, the value of the properties does look correct:

MSI (c) (B4:68) [10:05:27:331]: PROPERTY CHANGE: Adding NETFRAMEWORK40FULLINSTALLROOTDIR64 property. Its value is 'C:\Windows\Microsoft.NET\Framework64\v4.0.30319\'.

But the Registry entry is wrong:

MSI (s) (3C:28) [10:05:33:008]: Executing op: ActionStart(Name=WriteRegistryValues,Description=Writing system registry values,Template=Key: [1], Name: [2], Value: [3])
Action 10:05:33: WriteRegistryValues. Writing system registry values
MSI (s) (3C:28) [10:05:33:014]: Executing op: ProgressTotal(Total=1,Type=1,ByteEquivalent=13200)
MSI (s) (3C:28) [10:05:33:014]: Executing op: RegOpenKey(Root=-2147483646,Key=SYSTEM\CurrentControlSet\Services\EventLog\Application\ScholarshipSapQueue,,BinaryType=0,,)
MSI (s) (3C:28) [10:05:33:014]: Executing op: RegAddValue(Name=EventMessageFile,Value=##%C:\Windows\Microsoft.NET\Framework64\v4.0.30319\EventLogMessages.dll,)
WriteRegistryValues: Key: \SYSTEM\CurrentControlSet\Services\EventLog\Application\ScholarshipSapQueue, Name: EventMessageFile, Value: ##%C:\Windows\Microsoft.NET\Framework64\v4.0.30319\EventLogMessages.dll

Answer 1

That smells like a WiX v4 bug. Please open an issue at https://github.com/wixtoolset/issues/issues/new/choose.