Encoding failure in Media Encoder 2023

I got a failure in Media Encoder 2023. Log shows:

Export Error

Error completing render.

Writing with exporter: H.264
Writing to file: D:\Temp\TestVideos\z\Madama Butterfly\Madama Butterfly.Trial01.mp4
Writing file type: H264
Around timecode: 00:12:06:23 - 00:12:06:24
Component: H.264 of type Exporter
Selector: 9
Error code: 3

I used Premiere Pro 2023 v 23.2.0 (Build 69) to produce what I sent to Media Encode. All done on Win10 x64 Pro.

Any ideas?