[wix-users] How to allow version downgrade

[Swatantra Yadav]

Hello All,

I am trying to build an installer that would allow both upgrade to higher version as well downgrade to older version.

So I added the below to wxs file:
<MajorUpgrade AllowDowngrades="yes" IgnoreRemoveFailure="yes" MigrateFeatures="yes" Schedule="afterInstallExecute" />

While upgrade works perfectly fine, the downgrade from new version to old version is failing. I get the below error in error.log:

[475C:00D4][2019-01-17T23:02:25]e000: Error 0x80070666: Cannot install a product when a newer version is installed.

In the new installer I have added an additional new component and have new condition for higher .Net framework version. Those are the only two changes from the old installer.

How can I make this downgrade work?

Thanks
Swat