I've got an WiX installer with AllowDowngrades="yes" in MajorUpdate.
If I install version 2, then install version 1, I'm getting an error 2753 and the files are not copied (I get an entry in Add / Remove programs for version 1 though).
FYI, the file to be installed has got the same version as the installer. Also, note that launching installer 1 again works fine on second attempt.
Any idea?
Note: GUIDs are set as follow:
<Product Id="*" ... Version="!(bind.FileVersion.Launcher)" ... UpgradeCode="42076B77-741F-4B80-BA43-E8721DE0E4AD">
<Package Id='*' ... />