"Copyright" policy?

I have downloaded a broken free plugins source code, it was made in 2015 and was very useful according to youtube videos and other social platforms, the problem was simply a deprecated function. I’ve fixed it, would I be allowed to reupload the plugin or would this breach some kind of rule.

Original Plugin: https://www.roblox.com/library/161301454/ROAD-CREATION-PLUG-IN-BUG-FIX

Have you tried contacting the owner? I don’t think you can unless they give you explicit permission. . . .

They are really popular and I wont be able to contact them.
Thanks anyway.