[OSM-talk] Merkaartor errors when uploading ways

[Alex S.]

Jason Reid wrote:
> A 412 error typically means that the request tried to delete something 
> that depends on something else (ex: tried to delete a node thats still 
> part of a way).

It's easy enough to get a 412 via JOSM, too.  You can avoid the dreaded 
412 by remembering to not delete the end node of a way until/unless 
you've done a download of the area immediately surrounding the node 
(zoom in tight if you want) to see if there's another way connected to it.