Negative file size?

Why would a file size be negative? Four files in the hotspot on a MikroTik I’m working with failed to load when the user visited the hotspot from their browser, and when I checked the files on the MT web server, the size was listed at -1009480892 B.

I understand that in some cases this can happen with large files (like a 2GB file represented as a 32-bit integer), but this file was 107KB.

Has anyone seen this before? Any ideas welcome!