Something problematic poses a problem or causes difficulties. Your ambitions to become the next great leader of Spain are great, but your inability to speak Spanish might prove problematic.
Around 1600, the word problematical was shortened and problematic was born. Perhaps they wanted to make it less problematic for spellers. It's an adjective that means tough, hard to solve, or even questionable. A flat tire in the middle of the desert would certainly be problematic, as would a star witness with a history of telling lies.