Duplicate symbol 'WixAction:InstallExecuteSequence/RemoveExistingProducts' found. This typically means that an Id is duplicated

Question

I am developing an installer project using WiX 3.9 toolset. I am trying to uninstall the previous version during the install of a new version. I tried the below one in product.wxs,

<Product Id="*" Name="WIXDemoApp" Language="1033" Version="1.0.0.0" Manufacturer="Man name" UpgradeCode="993d89e6-07ec-4d33-abc5-957360bc66e1">
    <Property Id="PREVIOUSVERSIONSINSTALLED" Secure="yes" />
    <Upgrade Id="89CF8BE7-05EE-4C7E-9EFC-0249DD260EBB">
        <UpgradeVersion
           Minimum="1.0.0.0" Maximum="99.0.0.0"
           Property="PREVIOUSVERSIONSINSTALLED"
           IncludeMinimum="yes" IncludeMaximum="no" />
    </Upgrade>

    <Upgrade Id="89CF8BE7-05EE-4C7E-9EFC-0041DD260EBB">
        <UpgradeVersion
          Minimum="1.0.0.0" Maximum="99.0.0.0"
          Property="PREVIOUSVERSIONSINSTALLED"
          IncludeMinimum="yes" IncludeMaximum="no" />
    </Upgrade>

    <InstallExecuteSequence>
        <RemoveExistingProducts Before="InstallFinalize" />
    </InstallExecuteSequence>
</Product>

I am getting this error:

error LGHT0091: Duplicate symbol 'WixAction:InstallExecuteSequence/RemoveExistingProducts' found. This typically means that an Id is duplicated. Check to make sure all your identifiers of a given type (File, Component, Feature) are unique.`

What was the problem and how do I fix it?

Answer 1

The most likely problem is, like the error stated, you have a "Duplicate Symbol"

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I noticed-- two Properties are labeled PREVIOUSVERSIONSINSTALLED, and another one has an ID also labeled PREVIOUSVERSIONSINSTALLED

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WiX could be confusing the two of your Upgrade IDs, seeing as the only difference between them are the numbers 0249 and 0041

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Beyond those, your code shouldn't have any problems-- Then again, you didn't provide all of your code, so there is possibly one or more duplicates, like the error said.

Answer 2

The Upgrade element schedules the RemoveExistingProducts action for you. Remove RemoveExistingProducts from your InstallExecuteSequence and the error should go away. https://wixtoolset.org/documentation/manual/v3/howtos/updates/major_upgrade.html

Upgrade uninstalls detected versions by default. If you only want to store the ids of installed versions in a property add the attribute OnlyDetect="yes". https://wixtoolset.org/documentation/manual/v3/xsd/wix/upgradeversion.html