[wix-users] Patch applicability logic getting messed up and causing product downgrade

[manish duggal]

Hi
We are seeing patch applicability logic not working correctly and leading to incorrect patch sequence getting applied. I looked at the following threadshttps://blogs.msdn.microsoft.com/heaths/2009/04/13/patch-applicability/ 

and Patch not installing on a particular previous patch 


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Patch not installing on a particular previous patch


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We are using PureWix and have following PatchFamily entry in patch<Fragment>      <PatchFamily Id="AgentUpdate" Version="$(var.ProductVersion)" Supersede="yes"/>          </Fragment>
var.ProductVersion is actually a file version and is incremented on daily basis. 
What I observe is that I can apply my older patch (1.4.0 version) over my newer patch (1.6.2). What am I missing? What check could prevent version downgrade from happening?
Appreciate quick help or pointer with wix detail to handle this downgrading issue.  

ThxManish