Changing the file names worked. Not sure what the issue was with the original file names.

Closing ticket.

Re-assigning to Nowlan Freese so that he can take a quick look. I don't think this is a bug we can fix in Jira, except maybe by upgrading to the latest released version of the Jira server software.

Update: Looking for the problem character:

Screenshot
Screenshot
Screenshot 2
Screenshot 20
Screenshot 2025
Screenshot 2025-07-24
Screenshot 2025-07-24 at
Screenshot 2025-07-24 at 1
Screenshot 2025-07-24 at 1.4
Screenshot 2025-07-24 at 1.41.
Screenshot 2025-07-24 at 1.41.50

Found it! The problem is that there is a "null" character between "50" and "P" (from "PM")

I can paste the value from my system into this comment box, but unless I type backspace between 0 and P, Jira throws an error.

Here, I entered the name of the file here, and backspaced between 0 and P:
Screenshot 2025-07-24 at 1.41.50PM.png

Here I again entered the name of the file, backspaced between 0 and P, and entered a space character:

Screenshot 2025-07-24 at 1.41.50 PM.png

I attempted to upload a file created by my system's screen capture software and got an error.
I tried to copy the name of the file into this comment, but got an error message.
I think there is something weird about the name of the file that is causing a problem with the MySQL database Jira is using.
Looking in the Jira log on the host, I found that the error is related to a problem with the file name.
Changing the file name to test.png solved the issue.
I think the problem is related to use of unrecognized or illegal characters in the file name.

cc: Nowlan Freese