Argh sorry about that. It looks like a bunch of radicals weren’t included in the data file in this release, so whenever it tries to load any of them it crashes. I’m not sure that happened, but I’m making a new release now to fix it.
It’s probably better for anybody else to hold off updating for the next day or so.
For lessons it’ll always order by level first, then by type (radical first). Is there another order that would be useful?