I have pretty much the same issue as…
Game won’t start - Technical Support - Heroes of the Storm Forums
For a few weeks now. Usually the game does start, but occasionally (such as now) it doesn’t even show the Streaming Data window. The Launcher thinks it’s running, but it’s not really doing anything. Right now it’s happening after playing a session of WoW. Restart resolves it.
There was a similar issue with WoW about a year ago which turned out to be a very faulty server - or so. It might also be that something interferes with communication, but it’s important to point out that it only really occurs after playing some other Blizzard game, including Heroes in a previous session.
I don’t have any special software installed.
Task manager says that Heroes is running somewhat, the occasional 0.5-2.0% CPU, 74.4 MB memory consumption (can help pinpoint the phase of failure), 0.2 MB/s disk use and roughly 0.5 Mbps network use. Indefinitely.
Turning off wifi pauses it, then turning it on continues the process. Battle.net update agent is also doing something occasionally.