Basest Base

Check the map again. If i remember right, when i got to the final hide out i think it appears as a different looking marker on the map compared to how the other mission marker's looked.

Really? All gang hideouts were shown on the map, and the game progress shows as 15 of 15 complete although when I completed the 14th I didn't get a small dialogue or prompt to go to the final Gang Hideout like with some of the previous side missions, could
this be why it hasn't triggered?

It still doesn't make sense why the game would show as 15/15 yet the achievement hasn't popped or why all 15 Gang Hideouts would be shown on the map if I have to profile citizens to reveal their location, I'm probably not the only one thinking this.

I'll continue playing and see if it pops when another achievement unlocks and let you guys know if it does or not.

You might have to profile citizens to pop the Gang Hideouts by listening to calls or reading SMS

OK I'm having the same problem.....

I've got 15/15 gang hideouts done and no achievement, it's been over 24 hours now and nothing! also when I look on my dashboard it's saying 73% complete for it. The game is saying 15/15!

Anyone have any idea's

I have a similar issue to you GazVickers - When I check the progression wheel it's listed as 15/15 Gang Hideouts complete yet on the achievement app it's only at 66%. Any suggestions welcome, although I'm hoping it'll just auto update when I unlock another
achievement for the game.