JMORG

I have a Hexxit server and I am currently using the most recent build of MCPC+ server on 1.5.2. I got most plugins to work, like essentials, worldedit, worldguard, ect. but when I try to install factions, or mcore, it doesn't even install a folder. It gives me the "Could not load 'plugins/mcore.jar' in folder 'plugins'. I have the latest version of java and JDK installed. I went into my command prompt and it said I am running the latest version of java, 7.51 or whatever. I tried installing the latest version of mcore and factions, the ones meant for 1.5.2, and the 1.7.4 alpha version of factions that doesn't require mcore. None of them work and all give me the same error. I see that a lot of Hexxit servers running the current server version has factions on it. I am confused.