I have a headcanon that Eric's parents died in a shipwreck while Eric was on board as well, and he is still traumatized and partially blames himself for their deaths since he survived, and that's why he has a bit of a hero complex.

They tied of a dreaded diseased called Disney and Fairy Tale Parents Syndrome. This disease especially affects mothers. In the 2015 Cinderella movie it came after Cinderella's mother like a wrecking ball out of nowhere. Such a dreadful disease. LOL

(But in all seriousness, probably from a sickness)

I don't know...either this or what KL has described.

Yeah, definitely shipwreck. Eric enjoys the sea, so I think he wasn't with them.(just like what happened with Elsa&Anna's parents).

I think they are alive in the little mermaid 2 we can Saw them There is a Man who looks like the king in Cinderella

I think whatever happened to them was undoubtedly sea related; ship wrecked somewhere and marooned, drowning at sea, or off sailing the around the world. I definitely think they're alive somewhere. Else we would have a King Eric. I favor the notion of them traveling and letting Eric take care of the kingdom; giving him an opportunity to lead and gain some experience. I like disnerdtobe's thought. Off excluding Weselton from trade. :)