When I tried to update this script, I always got 500 (other scripts seem fine). Here's what happened after I've clicked that Post new version button:
The browser returned 500.
The actual code is updated, but the "Updated" time remains the same.
The displayed description is not updated, but when you try to update again, the editing area of description is what you're trying to save the previous time.
Also, attachments cannot be uploaded and displayed normally.
This was because it was trying to record the @require you were using. What you have is 263 characters long, but the limit was 256. I've increased the limit.
When I tried to update this script, I always got
500
(other scripts seem fine). Here's what happened after I've clicked thatPost new version
button:500
.