Having problems opening cbr/cbz files

I use a program called Simple Comic to open .cbr and .cbz files which are just .rar/.zip files under different extentions. I used to be able to open them no problem, but one day about two months or so ago my Macbook crashed on me suddenly. I restarted and when I tried to use Simple Comic the program would not open cbr/cbz files from outside the program anymore. By that, I mean I have to go to file > open within the program to open the files now, rather than just double click. I have no idea what kind of problem this could be, and I haven't noticed any other side effects from the crash except this one. I thought it may be a problem with the app itself but I uninstalled it multiple times and did my best to clear traces of it off the computer but every time I reinstall it has the same problem, which makes me think it's not the app. It's very frustrating to have to go into file > open every time I want to open a file, so help would be very much appreciated.