That can be all sort of things, and none of us peers are omniscient.
So you would need to give us some data to help sort out what happened. Like OS/CPU/RAM/GPU, the media used in that project, the effects used on that sequence, where in the export it went bad, that sort of thing.
At times, you get a time-code statement in the error message, and if you go to that point, redo/replace the work, it fixes whatever corruption may have occurred.
But you have to give us information to be able to help you.