Starting Dorian's Companion Quest

After several hours of playing around with it, I FINALLY got the quest to trigger. Based on my experience and what others here have said, I really think the issue is having JUST the right amout of positive favor with Dorian, not too little and not too much (dumb, right? It should be available starting at a certain amount and above--I hope Bioware fixes this soon). I wish I could say exactly what I did to make it trigger, but I can give you the ballpark (note that I sided with the Templars and therefore didn't recruit Dorian until Skyhold): I completed both the "Dorian's Request" and "A friend in Qarinus" War Table missions. Then I headed to the Hinterlands with Dorian and completed a SINGLE portion of the One Less Venatori quest. Then I went back to Skyhold and talked to Dorian, which got me the Felix scene. In a previous save I tried completing the whole Venatori quest before talking to Dorian--no dice. I also tried talking to him immediately following the War Table missions and before starting the Vinatori mission--nope. This would explain why people who talked to Dorian at Haven are having issues, because they may already have too much favor by the time they reach Skyhold. For me, even the amount of approval I got from just regular conversation and the Venatori quest seemed to put me over the limit. 

Since I sided with the Templars, I can't speak to whether specific actions at Haven have anything to do with the bug. I don't know if talking to other people before or after Dorian at Skyhold matters, either; in fact, in the save game I got it to work in, I had already talked to everyone, including Varric on the battlements. Also, since I hadn't recruited Dorian by the "Corypheus must be stopped" line, that doesn't seem to be an issue either. There really just seems to be a small window where you can get the scene, and after that you're locked out, unfortunately. 

Anyway, I just wanted to post this in case it helps someone. I would say if you're way past Skyhold's discovery and don't have any nearby saves, go ahead and don't waste your time trying to make this ridiculous thing work. But if you're around that point, don't give up, try what I did and other Dorian-related actions, and see if you can find the right amount of approval to trigger the quest. Here's hoping there's a patch soon!