Board Thread:LotR Mod Technical Support/@comment-26539210-20150719173101/@comment-89.20.252.59-20150811185349

The main thing, i think, is that 1G of RAM is no longer enough to launch the mod. I had to raise it to 1300M on my son's computer to get it working.

Try replacing -Xmx1G by something higher.

Also, in the trace above, the Forge version is outdated, and there's a more recent Java version (although that last one is more important for general security reasons rather than as a solution to this pb)