Downgrading an MSIX-installer application after setting ForceUpdateFromAnyVersion

Question

We have an application that we distribute internally on a network share with an MSIX package. We make the MSIX package with the MSIX project type in Visual Studio. Users install it with the index.html page that is created.

We want to rollback changes in case an update goes seriously wrong, so I've created an .appinstaller template and use it to set the ForceUpdateFromAnyVersion flag.

My question is how does a user actually perform a downgrade? I've tried to browse to an earlier version in Windows Explorer and execute the .msixbundle file, but it tells me that a newer version of the app is already installed and my only option is to launch the currently installed version.

I've only just discovered this ForceUpdateFromAnyVersion flag last week and we create weekly releases, so the version that has that flag set is the current version. Is that the reason downgrading doesn't work?

Answer 1

To perform a downgrade, place the appinstaller file on the share near the MSIX/MSIXBUNDLE and instruct the users to install the application via the appinstaller file (double click the appinstaller).

Only then the downgrade scenario will work. The msixbundle does not contain the ForceUpdateFromAnyVersion and it's not aware of it unless you use the appinstaller, that is why, when you try to downgrade via the msixbundle you receive the error that a new version is present on the machine.

What you must consider is this: if the user installed the MSIX/MSIXBUNDLE first, and then you publish the appinstaller file with the old version on your share, the downgrade will not happen automatically, because the MSIX on the user machine does not know that he has to check any share for updates/downgrades. All of the auto-update options are defined in the appinstaller.

But if your users installed the application via the appinstaller first, you can then put a new appinstaller file on your share (and MSIX/MSIXBUNDLE of course) which points to a lower version, and depending on how you defined the check interval in the appinstaller file, the downgrade will be performed automatically..

Answer 2

From what I read (I didn't test it) it seems that indeed the flag needs to be present in the appinstaller of the version that is checking for updates (not just in the new version). So, with the next update you should be able to push an downgrade.

Here is a more details tutorial from Microsoft on MSIX downgrades.