You can see in your log these lines:
Java frames: (J=compiled Java code, j=interpreted, Vv=VM code)
j org.lwjgl.system.JNI.invokePV(JJ)V+0
j org.lwjgl.system.jemalloc.JEmalloc.nje_free(J)V+6
j org.lwjgl.system.MemoryManage$JEmallocAllocator.free(J)V+1
j org.lwjgl.system.MemoryUtil.nmemFree(J)V+4
j org.lwjgl.system.Struct.free()V+4
j com.jme3.system.lwjgl.LwjglWindow.createContext(Lcom/jme3/system/AppSettings;)V+567
j com.jme3.system.lwjgl.LwjglWindow.initInThread()Z+36
j com.jme3.system.lwjgl.LwjglWindow.run()V+32
j java.lang.Thread.run()V+11
v ~StubRoutines::call_stub
This was only in 0.7.4