I don't really know what the problem is but I can tell you what MRJ is.
MRJ means MacOs Runtime for Java, you need this to run Limeware becaus LW is an app constructed with the Java programming language. This also why LW is a cross-platform app, Java can be read on a PC as well as on a Mac.

I had the same problem when I first installed LW. When you download LW it checks if you have the correct MRJ running on your Mac. If you do'nt LW will download this first before it will download the actual app itself. Maybe this is where it's gone wrong. What helped for me whas that I downloaded the latest MRJ from the official Apple website first and then downloaded LW.
NOW IT WORKS PERFECTLY!!!

Sorry for the spelling I don't usualy speak english.