I've never had any issues with opening it using winrar in the  past, but every time I try to open up the latest version, all I get is a popup as for qmindmap. I download it, extract the files to a new folder, wait a few seconds, and boom, popup appears. No idea why this is happening so if anyone has figured a work around or is also having this issue, please help.

If you try to extract some other RAR, do you get the same popup?  There's a description of that issue here - https://discussions.apple.com/thread/8214848  Seems to have something to do with the app you're using to extract the rar.