Hi. I downloaded nei-lotr from github, and added the NEI and LOTR jars in the libs directory. However, when I attempt to do "gradlew runClient", I get a long stacktrace, ending with "Caused by: java.lang.ClassFormatError: Duplicated LocalVariableTable attribute entry for 'this' in class file net/minecraft/entity/player/EntityPlayer". I think I have the correct versions of the jars etc.
You need the deobfuscated versions of the JARs (this applies to every dependency you have, which means, also the LOTR Mod and so on). The MC community has utilities (to example BON) whith which you can achieve that. Also, you probably need to call `gradlew setupDecompWorkspace` when you drop new jars to the lib directory.