I was trying to upload a new version of this file (a Science Summary CC BY audiovisual summary for a month) here.

Problem 1: I could not upload the full-size render because the UploadWizard had an error, without any meaningful description, after it finished uploading even though the file was smaller than this video that I uploaded for which the upload went through.

Problem 2: In the "Source file" when uploading the file from the local computer there is a "Maximum file size: 100 MB" which is smaller than the original file.

(Relevant notes: Despite of that videos should be automatically embedded, or even publicly hosted, with smaller rendered version in pages and only the largest renderings uploaded the commons, I tried uploading with a far lower-quality rendering for a short-term solution until this gets fixed but even that was 104 MB in size and there are some problems with the melt-renderings/Kdenlive that make running these problematic.)

Problem 3 (this issue): because of Problem 2 I uploaded the .webm video to archive.org here and tried uploading via this URL. Next to the upload via Source URL it says: "Maximum file size: 4 GB" (the file on archive.org is smaller than that and not even the full-size render). It then loads for a while after which it displays an error page with the error "Error: 413, Request Entity Too Large".

Once problem 3 is solved, issues for problem 1 and 2 could get created as separate tasks and linked to from here.