Lack of Space if on steam is usally the reason it would fail. Depending on how the game patches you will need its install space twice to patch.
I had that. Social club is trying to update, do it manually - I forget where I downloaded it in the end though!
It was a very widespread issue with 1.34, just do these and you should be fine. http://patches.rockstargames.com/prod/socialclub/Social-Club-v1.1.9.5-Setup.exe http://patches.rockstargames.com/prod/gtav/Installer/Launcher/GTA_V_Launcher_Upgrade_1_0_757_4.exe