Just some portions to save space. Original is +9MB. I use ............. to devise the blocks. ProblemType: Crash Architecture: amd64 CurrentDesktop: GNOME-Flashback:Unity Date: Thu Sep 15 17:14:41 2016 DistroRelease: Ubuntu 16.04 ExecutablePath: /usr/lib/virtualbox/VirtualBox ExecutableTimestamp: 1473699939 ProcCmdline: /usr/lib/virtualbox/VirtualBox --comment Winola --startvm a6b98d19-032f-4888-94d0-1dac9028df5e --no-startvm-errormsgbox ................... Uname: Linux 4.4.0-36-generic x86_64 UserGroups: adm admin audio cdrom ctbankix dialout fax floppy fuse libvirtd lpadmin netdev plugdev sambashare sudo tape vboxusers video wireshark www-data ................... Package: virtualbox-5.1 5.1.6-110634~Ubuntu~xenial [origin: Oracle Corporation] PackageArchitecture: amd64 ProcVersionSignature: Ubuntu 4.4.0-36.55-generic 4.4.16 Registers: rax 0x0 0 rbx 0x7fe874d59479 140636369294457 rcx 0x0 0 rdx 0x7fe874d4ed30 140636369251632 rsi 0xffffffff 4294967295 rdi 0x7fe874d5bd70 140636369304944 rbp 0x7fe85557aeb0 0x7fe85557aeb0 rsp 0x7fe85557ae90 0x7fe85557ae90 r8 0x0 0 r9 0x0 0 r10 0x7fe891334350 140636845196112 r11 0x246 582 r12 0x7fe874d58e10 140636369292816 r13 0x0 0 r14 0xffffffff 4294967295 r15 0x7fe874d5ced0 140636369309392 rip 0x7fe89133910a 0x7fe89133910a eflags 0x10202 [ IF RF ] cs 0x33 51 ss 0x2b 43 ds 0x0 0 es 0x0 0 fs 0x0 0 gs 0x0 0 SegvAnalysis: Segfault happened at: 0x7fe89133910a: callq *0xe8(%rax) PC (0x7fe89133910a) ok source "*0xe8(%rax)" ok destination "(%rsp)" (0x7fe85557ae90) ok Stack memory exhausted (SP below stack segment) SP (0x7fe85557ae90) ok Reason could not be automatically determined. SourcePackage: virtualbox-5.1 Stacktrace: #0 0x00007fe89133910a in ?? () from /usr/lib/virtualbox/VBoxDD.so No symbol table info available. #1 0x00007fe891334553 in ?? () from /usr/lib/virtualbox/VBoxDD.so No symbol table info available. #2 0x00007fe8d08965ec in ?? () from /usr/lib/virtualbox/VBoxRT.so No symbol table info available. #3 0x00007fe8d091fe7b in ?? () from /usr/lib/virtualbox/VBoxRT.so No symbol table info available. #4 0x00007fe8d11cd6fa in start_thread (arg=0x7fe85557b700) at pthread_create.c:333 __res = pd = 0x7fe85557b700 now = unwind_buf = {cancel_jmp_buf = {{jmp_buf = {140635840952064, 2796009831720795541, 0, 140637161940975, 524288, 140636369309392, -2801865073139139179, -2802138259662193259}, mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x0, 0x0}, data = {prev = 0x0, cleanup = 0x0, canceltype = 0}}} not_first_call = pagesize_m1 = sp = freesize = __PRETTY_FUNCTION__ = "start_thread" #5 0x00007fe8d0cffb5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109 No locals. StacktraceAddressSignature: /usr/lib/virtualbox/VirtualBox:11:/usr/lib/virtualbox/VBoxDD.so+bf10a:/usr/lib/virtualbox/VBoxDD.so+ba553:/usr/lib/virtualbox/VBoxRT.so+fe5ec:/usr/lib/virtualbox/VBoxRT.so+187e7b:/lib/x86_64-linux-gnu/libpthread-2.23.so+76fa:/lib/x86_64-linux-gnu/libc-2.23.so+106b5d StacktraceTop: ?? () from /usr/lib/virtualbox/VBoxDD.so ?? () from /usr/lib/virtualbox/VBoxDD.so ?? () from /usr/lib/virtualbox/VBoxRT.so ?? () from /usr/lib/virtualbox/VBoxRT.so start_thread (arg=0x7fe85557b700) at pthread_create.c:333 Tags: xenial third-party-packages ThreadStacktrace: . Thread 36 (Thread 0x7fe857cea700 (LWP 14250)): #0 pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 No locals. #1 0x00007fe8c6092fa4 in VBoxNsprPR_WaitCondVar () from /usr/lib/virtualbox/VBoxXPCOM.so No symbol table info available. #2 0x00007fe8c6093234 in VBoxNsprPR_Wait () from /usr/lib/virtualbox/VBoxXPCOM.so No symbol table info available. #3 0x00007fe8a79dec1b in ?? () from /usr/lib/virtualbox/components/VBoxXPCOMIPCC.so No symbol table info available. #4 0x00007fe8c6081685 in ?? () from /usr/lib/virtualbox/VBoxXPCOM.so No symbol table info available. #5 0x00007fe8c6091bc9 in ?? () from /usr/lib/virtualbox/VBoxXPCOM.so No symbol table info available. #6 0x00007fe8d08965ec in ?? () from /usr/lib/virtualbox/VBoxRT.so No symbol table info available. #7 0x00007fe8d091fe7b in ?? () from /usr/lib/virtualbox/VBoxRT.so No symbol table info available. #8 0x00007fe8d11cd6fa in start_thread (arg=0x7fe857cea700) at pthread_create.c:333 __res = pd = 0x7fe857cea700 now = unwind_buf = {cancel_jmp_buf = {{jmp_buf = {140635882301184, 2796009831720795541, 0, 140637200188431, 140635882301888, 140637731625734, -2801868172494914155, -2802138259662193259}, mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x0, 0x0}, data = {prev = 0x0, cleanup = 0x0, canceltype = 0}}} not_first_call = pagesize_m1 = sp = freesize = __PRETTY_FUNCTION__ = "start_thread" #9 0x00007fe8d0cffb5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109 No locals. ................... Thread 1 (Thread 0x7fe85557b700 (LWP 19180)): #0 0x00007fe89133910a in ?? () from /usr/lib/virtualbox/VBoxDD.so No symbol table info available. #1 0x00007fe891334553 in ?? () from /usr/lib/virtualbox/VBoxDD.so No symbol table info available. #2 0x00007fe8d08965ec in ?? () from /usr/lib/virtualbox/VBoxRT.so No symbol table info available. #3 0x00007fe8d091fe7b in ?? () from /usr/lib/virtualbox/VBoxRT.so No symbol table info available. #4 0x00007fe8d11cd6fa in start_thread (arg=0x7fe85557b700) at pthread_create.c:333 __res = pd = 0x7fe85557b700 now = unwind_buf = {cancel_jmp_buf = {{jmp_buf = {140635840952064, 2796009831720795541, 0, 140637161940975, 524288, 140636369309392, -2801865073139139179, -2802138259662193259}, mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x0, 0x0}, data = {prev = 0x0, cleanup = 0x0, canceltype = 0}}} not_first_call = pagesize_m1 = sp = freesize = __PRETTY_FUNCTION__ = "start_thread" #5 0x00007fe8d0cffb5d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109 No locals. Title: VirtualBox crashed with SIGSEGV in start_thread() libsystemd0, libudev1