So I was in the middle of a heist when the power goes out. When I turn the console back on everything loads fine but when I press down dpad nothing happens other than map zoom out and street/vehicle name on the bottom right. No character switch wheel. Also, there are no missions on the map for me to go to for my currently selected character.
So essentially I am stuck. I tried loading another save file and I can switch characters just fine. I don't know what else to do.
Unfortunately it must have froze mid-save and corrupted that save data somehow. You will have to go back to the older save and start from there, that sucks man . Its also why I, like you, have multiple save files....just in case!