Forums Help Desk Stuck on Gta v


I have a problem with Gta Story Mode. I'm now almost in the half of the missions but i can't go furhter. Normaly you have missions with a letter for exemple L(headmissions) but i have only missions with a ? and a letter for exemple B?. My friends have told me that you don't have to play the B? (submissions) to play the game out. Can someone help me please? Thank you!

What was the last storyline mission you've done?

Eye in the sky