Originally Posted by Treylina

Okay, I'm going to ask more questions:

Did you extract all the plus files out of the Zip, and put them inside the corresponding JJ2 folder? This is essential. For convenience and making sure you don't miss anything, use Ctrl + A to copy all files.

After that, did you use plusifier? You also need this to make plus. It'll create jazz2+ exe. If you try to use plusifer when the plus contents aren't in the jj2 folder (and having the zip itself in the folder doesn't count, you have to extract it), it won't work.

I also advise getting the October 2013 version. It hotfixes some annoying bugs.

If you get the application error when opening JJ2+, that's a normal plus bug. There's a way to work around that.