I was on the phone with support, but I guess they close at 6PM EST, and at 6PM on the dot the line went dead in the middle of the call. I don't think they were really able to help me anyway, since it's obviously a problem with the codebase, and not something like a browser setting.
"selectTopicList not found"
I'm guessing that this is a debug error handler left in the code, though I obviously can't say what's triggering it.
I've tried in Chrome, Firefox, and Safari, on two different machines, and the behaviour is consistent. I was surprised that the support agent hadn't already fielded calls about this, as if it was happening to everyone, it's kind of a blocker and nobody would be able to file their taxes, so it could be something specific to my account.
Anyway, I'd like to file my taxes, and I've gone far enough in TurboTax that I don't really want to start over with another product, so resolving this would be ideal.
If anyone has any ideas, or if the dev team needs any additional information from me, please let me know.