Sibrius

Trying to run the modpack stoneblock2

Sorry if I am posting this in wrong spot hoping someone can help me with an error, trying to run stoneblock 2 modpack, when I run it I get the following error message. The game is running. Please wait. Error: Could not create the Java Virtual Machine. Error: A fatal exception has occurred. Program will exit. Invalid maximum heap size: -Xmx4096M The specified size exceeds the maximum representable size. Process ended with code: 1 Just bought a server and can't play it until I can figure this out. Thanks

I I'm having the same problem at the moment. Any help possible?