Factorio 0.18.22
Dirt Path 1.3.4

I was zoomed out so I don't know the exact circumstances but got this almost as soon as I started moving on a freshly loaded map.

http://bitviper.org/factorio/2020-05-24_200604.png

Looks like I forgot to mark earlier versions as incompatibile. Dirt Path 1.3.4 uses a new feature not available in 0.18.22. You can either update Factorio or use an older version of Dirt Path.

Thanks for the prompt response. I wondered if it might be something like that. I've had a hard time keeping up with the weekly version updates because my internet is stupid slow. =(