We just discovered this issue today.  So, was VMware telling you to go through and update your AppStacks, or do you have to rebuild each one from scratch?  I just went through ours, as re-saving them fixed some other problems we were having with 2.14.  I noticed that when I go to update any of our AppStacks, it disables the Windows Search service on the provisioning VM I'm using.

I have been trying the GPO mentioned in this thread to push out those two registry keys to our VMs in the pools as well as the VMs we use to provision the AppStacks with.  We do not want Windows Search disabled here at all, as our users heavily rely on it and it's causing a bunch of problems when the service is not running.

On the VM we use to provision the AppStacks, the registry values are being pushed to it just fine and the Windows Search service is running, but when I try to update an existing AppStack on it, the "preparing to provision... please wait" box comes up and stays there, and the process does not continue.  If I restart the AppVol service on this VM, it changes the values of the registry back to zero.  So far I'm stuck and cannot seem to get our provisioning VM working in order to update the AppStacks, if that is truly the fix?

Thanks for your help.