virtualbox and centos 7 cannot run headless.

[boxxofrobots]

I have a 40 core centos 7 server with 256GB RAM (30% ram and two cores used) I have been trying hours to get running properly. It appears vagrant and virtualbox are installed, but the headless function is NOT working. When I try to run a vm (I have tried several) I get a failure

!!Assertion Failed!!
Expression: RT_SUCCESS_NP(rc)
Location : /home/vbox/vbox-5.1.22/src/VBox/Runtime/common/misc/thread.cpp(812) int RTThreadCreate(PRTTHREAD, PFNRTTHREAD, void*, size_t, RTTHREADTYPE, unsigned int, const char*)
VERR_TRY_AGAIN (-52) - Retry the operation.
Trace/breakpoint trap

vagrant gives me this:

==> default: Checking if box 'ubuntu/trusty64' is up to date...
==> default: Clearing any previously set forwarded ports...
==> default: Clearing any previously set network interfaces...
==> default: Preparing network interfaces based on configuration...
default: Adapter 1: nat
==> default: Forwarding ports...
default: 80 (guest) => 8931 (host) (adapter 1)
default: 22 (guest) => 2222 (host) (adapter 1)
==> default: Running 'pre-boot' VM customizations...
==> default: Booting VM...
There was an error while executing `VBoxManage`, a CLI used by Vagrant
for controlling VirtualBox. The command and stderr is shown below.

Command: ["startvm", "0d6f843f-4a57-44fd-8082-31d668562252", "--type", "headless"]

Stderr: VBoxManage: error: The VM session was aborted
VBoxManage: error: Details: code NS_ERROR_FAILURE (0x80004005), component SessionMachine, interface ISession
"v.gui= false"
When I check the logs, it all comes back to can't find an xorg server to attach to. Note this happens even when vagrant is set for "gui=false" or when virtualbox healdess is run from command line (see above). There were no errors installing once the proper headers were installed for the kernel, and I have reinstalled the addons package, again without error or warning. I have tried various searches and most of them simply say "the server is overloaded" or "install XVRT. I have done both, neither works.

[boxxofrobots]

If this helps...

uname -r
3.10.0-514.26.2.el7.x86_64

cat VBox.log
VirtualBox VM 5.1.22 r115126 linux.amd64 (Apr 28 2017 19:53:24) release log
00:00:00.012798 Log opened 2017-07-08T03:13:54.493244000Z
00:00:00.012799 Build Type: release
00:00:00.012802 OS Product: Linux
00:00:00.012802 OS Release: 3.10.0-514.26.2.el7.x86_64
00:00:00.012803 OS Version: #1 SMP Tue Jul 4 15:04:05 UTC 2017
00:00:00.012817 DMI Product Name: X10DRH
00:00:00.012821 DMI Product Version: 123456789
00:00:00.012923 Host RAM: 257676MB (251.6GB) total, 184747MB (180.4GB) available
00:00:00.012944 Executable: /usr/lib/virtualbox/VBoxHeadless
00:00:00.012945 Process ID: 25395
00:00:00.012946 Package type: LINUX_64BITS_EL_7
00:00:00.013896 Installed Extension Packs:
00:00:00.013902 Oracle VM VirtualBox Extension Pack (Version: 5.1.22 r115126; VRDE Module: VBoxVRDP)
00:00:00.014442 Console: Machine state changed to 'Starting'
00:00:00.016613
00:00:00.016614 !!Assertion Failed!!
00:00:00.016615 Expression: RT_SUCCESS_NP(rc)
00:00:00.016615 Location : /home/vbox/vbox-5.1.22/src/VBox/Runtime/common/misc/thread.cpp(812) int RTThreadCreate(PRTTHREAD, PFNRTTHREAD, void*, size_t, RTTHREADTYPE, unsigned int, const char*)
00:00:00.016640 VERR_TRY_AGAIN (-52) - Retry the operation.