It looks like something breaks on some step of exporting the map (either when creating a hi-res version of it, or while writing it to a file). Have you checked your browser console? It's just odd that this doesn't cause any messages there. And the problem is that this city of your is exported normally for me...
2 years ago(+1)
Apologies for the delay replying -
The export to png works for this town in Chrome and Edge - it doesn't work consistently in Firefox.
I've put an image of the console output when it fails on firefox - hopefully this is useful for you!
OK, for some reason this log doesn't look as readable as it should, but I'm pretty sure the generator breaks because the exported map is too large (in pixels, not in meters, buildings or anything like that). I'll try to come up with a fix for it without sacrificing too much of image quality. Thanks!