I have a new installation of Multicraft with four (4) servers, and I can run any of the four one-at-a-time with no problems...but then the following shows up in the Multicraft console whenever I attempt to start a second server:
[Server] INFO #
[Server] INFO # There is insufficient memory for the Java Runtime Environment to continue.
[Server] INFO # Cannot create GC thread. Out of system resources.
The info at the first link below looks to me like that might be an easy solution, but then the info in the link following that makes me want to investigate further rather than possibly just applying a band-aid patch of whatever kind that does not address the real issue...