Wordpress store seems like a recipe for disaster. Im sorry but this software needs CONSTANT updates because it has more holes than swiss cheese.
Problem with plugin is no suprise to me, maybe try to extract private key, then finish operations through wallet software to skip buggy plugin.

"You just replied in an old topic" <-- yeah, its good to reuse sometimes old topics but not in this case you should made ur own topic with your problem. Got me confused.