Just a little note to tell you guys I updated my Impulse hair with a new thumbnail cause a lot of ppl where having troubles with the old one.
If you had issues with the thumbnail all you need to do is download it once again and just in case clear your cache before entering the game next time.
(If the thumbnail is showing for you, you got the new version)
Clearing cache will also make the old thumbnail work but I would still suggest redownloading.
If you dont know how to clear cache all you have to do is just go to Documents/Electronic Arts/The Sims 4/ find a package called ''localthumbcache'' delete it and simply load the game ;)

Love, Nightcrawler <3