Firmware Update File Error

I have a couple of node types to update to the 3.16.1.1 version, so I downloaded the ones I needed, but I renamed them so I could easily see which file went to which node type.
When I tried to update, the node wouldn't take the file.

I checked the hash when I downloaded, but figured I'd just get a new copy, which uploaded just fine.
I compared the hashes, and they were the same.

So, I take it there is a file name verification for upload, in addition to or instead of other verification methods?
I thought this had worked previously, but it's been a while, so I can't be sure.  Perhaps it was loading AREDN onto stock hardware.

Cheers.