BattlEye detects that your game’s or system’s memory is not what it is supposed to be. Close all unnecessary programs running on the system, scan your system for viruses/trojans/spyware and check your RAM for possible defects (using tools like Memtest86). If that doesn’t help a full repair reinstallation of your system is likely needed.
This answer is copied from BE's FAQ and slightly adapted to be Unturned-specific. Click here to visit the BE support page.