The launch of the Grand Theft Auto 5 multiplayer reportedly corrupts single player saves.
MCVUK reports that multiple users, including editors from Eurogamer.net, found corrupted single player saves when accessing the multiplayer. Some of the reported issues involve single player saves jumping ahead in the story, bringing players to plot points not previously reached.
The launch of Grand Theft Auto 5 caused a number of other issues including an inferior digital PS3 version and frozen Xbox 360 consoles.
We await official confirmation of the save file issues.