Windows Update finished. Now I'm at 285.
Ran Arduino 1.8.7 with Teensyduino 1.44-beta2. Uploaded the WAV player example to a Teensy 3.6. Everything seems to be working fine. Here's a screenshot.
View attachment 14728
Something you might notice in this screenshot is the Ports menu now (since 1.42) has a section specific to Teensy. If your Teensy is running a non-Serial program, it will still properly display in this area. The normal Serial part only detects Teensy when it's running USB Serial code.