It looks like starting today the Bing imagery servers are returning 404s for tiles that look like:
which is a correct url based on template returned by their metadata service:
Sometimes it returns g=999 which results in tiles that work. g= in the url indicates which generation of imagery to use, it looks like they increment it every time the imagery is updated so that cached images are invalidated. As far as I can tell, this problem is entirely on their end (it looks like somebody forgot that numbers can go higher than 3 digits)
The actual Bing Maps web interface seems to be broken too, this map comes up blank for me and the console fills with 404s:
Hopefully they’ll get this fixed soon. Anyone have contacts at Microsoft?