Reddit thread has extra info, including dev mode troubleshooting. No known solution, aside from dev forcing caravan. - https://www.reddit.com/r/RimWorld/comments/fk8ruq/your_caravan_is_unable_to_leave_the_area_any/
Here is an album showing my map, the error, and my route (im northeast, by ocean.) No direction besides north is blocked on my map (ocean.) My colony even has a dirt road leading to my caravan destination...
https://imgur.com/a/xZEGA6A
I have a few mods, all updated to 1.1, and none that interact with or affect caravans. I've disabled all mods resulting in no change. Any ideas as to what I can try? Just a tribe, so drop pods are a little ways away.
As for what I've tried...difference colonists, different caravan forming spots (yellow placeable square,) and every route/waypoint direction.
Thank you.
Edit: Going to make a new save and dig out the western rock to see if that helps.
No luck digging out the rock. Visitors are leaving via western side, if that means anything. https://imgur.com/a/LaDbsvp
I've now dug out 2 block wide tunnels, with no luck. East, south, west are all open on my zoomed in map. https://imgur.com/hOcene8
Apologies, this should have been in "bugs"
Save file is too large to post.
This bug was fixed two weeks ago. The known solution is to update. The link you got in the mail when you purchased the game always has the latest version.
[Royalty 1.1.2558] Unable to form a caravan. "Make sure one side is reachable" (https://ludeon.com/forums/index.php?topic=50591)