I tested with the MicroServer_Java simulators and had no issues so we need to look at your environment as the possible cause of the problem.
Are you running the simulators from the same machine that ThingWorx is installed on? What o/s are you running on? Do you possibly have a 32-bit version of java installed that it's trying to use? Is the JAVA_HOME environment variable pointing to a 32-bit version?
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