How to unlock Lamar, Ron, Trevor, Martin, etc missions?

[nomnomnom]

As per title say, how to unlock these guys' mission? Currently Im level 50, complete the tutorial, and havent even host a single heist before. I surf through internet but I can't see real solution. Please someone help me!!

[eQuals42]

The only way i know is to ask somebody that has Ron and/or Trevor missions and invite you into one of their missions. After you play one mission and exit to a session wait for Ron to call you. That's how i manage to deal with this glitch, now i can call Ron and request jobs. But still i cannot find Ron's missions in the job lists(Rockstar Created/Missions)

[Northwind_JME]

Pause/online/jobs/rockstar created/missions is there anything there? If there is then try playing one of them it could be a bug. It is odd that you are level 50 without having played heists or contact missions. (I can only assume you've leveled up another way.) Are any of those people in your phones contact list? Try phoning them and ask for work.

[nomnomnom]

I've unlocked it already. Thx for the response!!