I’ve been using Scalar 2 successfully on my iPad Pro until recently. I don’t know if it’s that the iPad updated to iPadOS version 16.4.1 (a) or not, but that’s the only change of which I’m aware. The problem is 100% reproducible:
Launch Scaler 2 and tap the settings gear once you’re in the app.
Tap “BLUETOOTH/MIDI SETTINGS” at the bottom of the resulting menu.
Tap the “MIDI Input” field in the resulting form and watch it crash.
It’s probably related that I used to have text saying “Network Session 1” or something like that in both of those fields, and they’re completely blank of late. Help?!
I’m replying to my own post because after a whole lot of troubleshooting I’ve found the issue. I don’t know what was wrong, but rtpMIDI on my Windows 10 Pro x64 PC was the problem. It didn’t matter how many times I ran “repair” on the installation and watched it finish without errors, the only proper solution was to uninstall it completely, reboot the machine, and then reinstall rtpMIDI from scratch. With that done, my iPad showed up immediately in the available participants and Scaler 2 no longer crashes. Yay!