You are way behind with patching up your kernel for all AX components, 6.3.2000.3787 is far away from the latest release:
blogs.msdn.microsoft.com/.../overview-of-microsoft-dynamics-ax-build-numbers
Microsoft will ask you to patch everything up before they would proceed with identifying the root cause.
After applying the hotfix, if you still experience the issue, identify what customizations you have. If this does not reveal the root cause you need to collect a Crash dump, and open a Support Incident with Microsoft, where you may upload the crash and they would do an analysis for you to tell what exception causes the problem.