I did it on Windows (after failing to get the Bitcoin.com app working on linux at all). I didn't get the same error message as you.I did get some strange network error, but I just turned everything off and on again a couple of times and it just worked in the end.
I’m gonna try it again maybe on my PC. I’m so irritated right now. Maybe another go on Mac first. feel like I’m not gonna see those coins again. And over a total non user error.
I got my money out but I'm also irritated. They can't just drop support for their own wallet format out of the blue like this. It shows complete disregard for their users.