Why was my photo ignored when I uploaded it?

The upload panel lists a file it cannot use in red, marked Can’t use, with the reason on its row. The usual reasons: the file is not a JPEG or TIFF (PNG, WebP and HEIC are not taken), it is not a full 360 photo (its width divided by its height is outside 1.9 to 2.1, as a crop is), a cube is missing some of its six faces, or it is larger than the size limit (23,000 pixels wide for a sphere, 16,000 for a cube face; a photo that a phone or a small computer sends to Panoramr's servers can be a sphere of 16,384 pixels at most). A photo with the same file name and contents as one already in the tour (or in the library, when you add from the Asset library's window), or that you chose twice, is not given a row: a line above the list says how many were left out and where, for example 10 of these are already in your tour and were left out., and Add it again adds one as a second panorama. A folder's files that are not photos are skipped, and not always with a line: choose the files themselves to see a reason for each. When you choose more photos than your account can still hold, only the first ones are added. No file is left out for how many megabytes it is when your computer makes the tiles: 250 MB or less works best, and a larger one is still taken, but takes longer and needs a recent computer with plenty of memory. A photo sent whole to Panoramr's servers (from a phone or tablet) is refused above 600 MB. Fix upload problems lists every message.