Ive been on a rooftop surrounded by unclimbable fences and stuck way off shore a lot of times throughout the game, and there is a very simple fix, and most of you probably know it already. All you do is start a mission, and then abort if you don't want to do it.
If you are in the middle of a mission or just running around than a Car hits you or you take a shot to the head and die you quickly Get out of the game and play another game for 10 minutes than Go back in to gangster it should of gone to the starting screen Than Tap resume game and than your should have as much Money as before.
Make shor you always save after every time you finish a mission Or start one
There are 3 ways to get easy money here they are 1). Go into bank take money use one of the cops cars outside or use the helicopter and loose the cops wait until bank is open again than repeat you only get $2500 each time or if you have a glitch to walk though walls use that put walk though the walls and land in the volt and take money than walk out though the wall and repeat much easyer
2). Kill drug dealer can be found near the boat house thing you get $2500 ASWELL and beware of his bodyguards bring lots of ammo
3). Kill the rich people (males in suits and guy in purple top you will see the guys I'm talking about there from the bank) they drive these cars bellow W4c, laufter, galapeno, sport car, limo I don't know what other cars they use but the two tunnels slide by side you will find that at the boat house here is what I do find any of the bank people in any of the cars I mentioned earlier and throw them out the car park on them quickly jump out of the car and $$$$$$ eventually you will get lots of money so ✌ out