This is a userscript that will download multi episodes form KissAnime.
< Feedback on KissAnime Downloader
Thanks for reporting this to me, this happened because rapidvideo changed their player. I've updated the script, hope it works for you! Thanks again.
Update?
Firstly thank you for this amazing script. Please have a look at it, it might need an update. It has been failing to capture links within .txt files and .html files. Thanks in advance.