I just went through a Change operation of Avast to research another post, and it ended up completing an update including a run of AvastEmUpdate.exe. At first I wondered if it would hang, since it stopped on that step for a few seconds, but then it completed.
Same here. After seeing your note, I tried a clean install on a Windows 7 SP1 virtual machine, using the 9.0.2011.263 Avast Free installer. The installation seemed to hesitate for a moment on AvastEmUpdate.exe /Installer (or maybe it was /Install), but after a few seconds, the installation completed successfully. (I don’t run MVPS, but I do filtering on my router, running a script that blocks ads based on a list of ad servers at pgl.yoyo.org.)
Someone from Avast did acknowledge that there was a problem, and I believe they said they’d work on it. I’ve lost track of the specific thread; it seems to me it may have been one of the pinned ones.