I'm on the latest version of dynmap for 1.15.2 and my console is being flooded by this error.

[dynmap] Image file plugins/dynmap/web/tiles/markers/marker_world_new.json - unable to write - failed

I've tried to cancel render, paused all renders, and the error still appears. Is there a fix?

This is a common bug but is likely due to permissions errors or config errors. Please reopen if the issue persists.