WiX error 2753 on upgrade

After hours of head banging into a wall : Error 2753 I found that my sexy custom action was the culprit because it had no ExeCommand set.

If you want to auto launch the application after install you may want to see a working sample:

 
 <InstallExecuteSequence>
      <Custom Action="LaunchApplication" Before="InstallFinalize" >UPGRADINGPRODUCTCODE OR REINSTALL OR NOT Installed</Custom>
    </InstallExecuteSequence>

...

 
 <Fragment>
    <CustomAction Id="LaunchApplication" FileKey="$(var.MainExeID)" ExeCommand="mustBeSomethingOrTheUpdateWillFailWithError2753" Execute="commit" Impersonate="yes" Return="asyncNoWait"/>
  </Fragment>