This problem has NOT been fixed. Avast still causing WoW-64.exe to not launch properly.
I haven't received anymore replies from support so after them telling me that I was the only person to report the problem, then that they couldn't duplicate it I am pretty sure I am just going to swallow my recent renewal for our household computers and move back to Norton/Symantec. Like you I have removed everything and re-installed it, tried disabling all shields and the only time that wow launches 100% of the time is when Avast is removed from my system.
I understand software glitches, I don't understand what I believe are customer service glitches.
John
Well I have found that if I reboot my computer, everything works fine, but only after a fresh boot. It works, but is NOT a fix. I suggested to them to get a free WoW account and use it for their troubleshooting. It was after this that they also stopped responding to me. We pay for the application, and I am happy to help them in troubleshooting problems, but for them to just stop responding it bad business. I will continue to use Avast until my current sub if done, but I may leave after that. Maybe by then they will find the glitch and get it fixed.
In another thread, someone had very similar problems when trying to play Overwatch. Wonder if the problems are related. I tried the possible fixes there (not mudh different than what we have already tried) with no success.