A particular Orange83 transition renders incorrectly in Media Encoder. It's one of these: https://sellfy.com/p/DXuM/

It plays back fine inside of Premiere Pro, and renders fine if the sequence isn't queued out to Media Encoder, but if it's queued out to Media Encoder, the blurring and motion effects aren't rendered--it just renders a kind of "cut zoom in."

Premiere Pro 12.1.1 (Build 10)
Media Encoder 12.1.1 (Build 12)
Microsoft Windows 10 Pro for Workstations
10.0.16299 Build 16299