C:\Tekkit servers\Tekkit_Server_3.1.2>java -Xmx=4G -Xms4G -jar Tekkit.jar nogui Invalid maximum heap size: -Xmx=4G Error: Could not create the Java Virtual Machine. Error: A fatal exception has occurred. Program will exit. I have tried uninstalling old versions of java and downloading the latest x64 java 8 to no avail. I'm running 16 gigs of ddr4 memory so the 4 should be a breeze. FIXED After an hour of fumbling i realized i needed to drop "=" from the Xmx line. Sorry to waste anyones time.