Animated drawing of my fursonas Hender (1st from left), Noggy (2nd), Hakiya (3rd) and Jacky (4th) waving to the reader

Fixing "Error loading this archive" when opening password protected .rar files with File Roller

Install the rar package with sudo apt install rar.

I only had this problem with Ubuntu, so I don't know if it also happens on other types of Linux distros.