Broken file uploads

[smaug5]

While making a news post, there were uploaded files that would be broken when checking "Förhandsgranskning" of the post. Deleting and re-upload worked for some of them, while some were not able to get uploaded directly after being deleted from the list. These took many retries to get uploaded, but it eventually worked out.
Additionally, some files broke after deleting and re-uploading another file.

Unsure how to replicate, wonder if it might be related to many files being uploaded at once.

[GAsplund]

Very strange. The preview of the post normally uses "queued" files locally and only actually uploads them once you submit the post. Are you also experiencing this when a news post has actually been submitted or is it just with local previewing?