You probably won't encounter this error very often as a Flickr user: the dreaded
414.
This is the kind of error you have to earn through hard work.
How does one create this? By generating incredibly long URIs after uploading a
batch of photos. In this case, I uploaded 1015 vacation photos using the Flickr Uploadr
tool. Well, it stalled out on the first try after around 100, so the batch that
caused the issue was closer to 900 photos.
After uploading the large batch, the Flickr Uploadr tool offers a link to the
freshly uploaded photos where you can start adding titles, descriptions and
tags. However, that page includes the Flickr photo ID of every newly uploaded
photo in the page's URL, and there is a limit to how long that URL can be. In
this case, it reached 10,029 characters. As I understand it, the limit is either
~2,000 or ~4,000 characters, so I was WAY out of range.
In the end, this isn't a big deal since the webpage provided by Flickr from the
Uploadr is a horrible interface for the volume of photos I uploaded.