It's time to experiment

Last month, I posted a plea for help to try to figure out why sometimes (or rarely) (or frequently), Windows Installer fails to set an internal property that causes a never-ending “please wait” dialog. I got lots of feedback—thanks!—but unfortunately, nothing that helped me pinpoint a cause or a solution.

So it’s time to make an guess. Let’s call it an educated guess but as I can’t reproduce the problem, I’m not sure it’s entirely educated.

Coming in the next weekly release of WiX is a mechanism to opt out of the costing popup dialog. And although it’s an opt-out mechanism, for now it’s opted-in by default. The idea is to see quickly if the change fixes the problem. If it does, we’ll keep the opt-in default for WiX v3.5. If not, we can either back out the change or just change the default to opt-out.

So what’s the change? Before, all the dialogs that initiated an install transaction used a SpawnWaitDialog control event with a condition of CostingComplete=1. The dialog would pop up until the condition was met. Now, the condition includes the bind-time WiX variable WixUICostingPopupOptOut. WixUICostingPopupOptOut defaults to 1, so the condition is always true and the popup never appears.

You can override WixUICostingPopupOptOut in your project with a value of 0 to return to the previous behavior:

<WixVariable Id="WixUICostingPopupOptOut" Value="0" />

So, please grab the next release of WiX and try out your previously problematic installers. We want to fix this problem before we start locking down WiX v3.5 for RTM.

Update: You can get the weekly release here.