X Fails to start - any help is appreciated

Xorg.0.log

[ 50.025] (==) Matched nvidia as autoconfigured driver 18
[ 50.025] (==) Matched nvidia as autoconfigured driver 19
[ 50.025] (==) Matched modesetting as autoconfigured driver 20
[ 50.025] (EE)
[ 50.026] (EE) Backtrace:
[ 50.026] (EE) 0: /usr/lib/xorg/Xorg (xorg_backtrace+0x4d) [0x55a7323f08ad]
[ 50.026] (EE) 1: /usr/lib/xorg/Xorg (0x55a732238000+0x1bc649) [0x55a7323f464
9]
[ 50.026] (EE) 2: /lib/x86_64-linux-gnu/libpthread.so.0 (0x7f44b6b01000+0x128
90) [0x7f44b6b13890]
[ 50.026] (EE) 3: /lib/x86_64-linux-gnu/libc.so.6 (0x7f44b6710000+0x18e5a1) [
0x7f44b689e5a1]
[ 50.026] (EE) 4: /lib/x86_64-linux-gnu/libc.so.6 (_IO_vfprintf+0x2143) [0x7f
44b676d4d3]
[ 50.026] (EE) 5: /lib/x86_64-linux-gnu/libc.so.6 (__vsnprintf_chk+0xa9) [0x7
f44b6842169]
[ 50.026] (EE) 6: /usr/lib/xorg/Xorg (Xvscnprintf+0x21) [0x55a7323fcb31]
[ 50.026] (EE) 7: /usr/lib/xorg/Xorg (LogVMessageVerb+0x66) [0x55a7323fe716]
[ 50.026] (EE) 8: /usr/lib/xorg/Xorg (xf86Msg+0x9c) [0x55a7322d849c]
[ 50.026] (EE) 9: /usr/lib/xorg/Xorg (0x55a732238000+0xb59da) [0x55a7322ed9da
]
[ 50.026] (EE) 10: /usr/lib/xorg/Xorg (InitOutput+0xa5c) [0x55a7322d10bc]
[ 50.026] (EE) 11: /usr/lib/xorg/Xorg (0x55a732238000+0x56cd3) [0x55a73228ecd
3]
[ 50.026] (EE) 12: /lib/x86_64-linux-gnu/libc.so.6 (__libc_start_main+0xe7) [
0x7f44b6731b97]
[ 50.026] (EE) 13: /usr/lib/xorg/Xorg (_start+0x2a) [0x55a732278b8a]
[ 50.026] (EE)
[ 50.026] (EE) Segmentation fault at address 0x0
[ 50.026] (EE)
Fatal server error:
[ 50.026] (EE) Caught signal 11 (Segmentation fault). Server aborting
[ 50.026] (EE)
[ 50.026] (EE)
Please consult the The X.Org Foundation support
at http://wiki.x.org
for help.
[ 50.026] (EE) Please also check the log file at “/var/log/Xorg.0.log” for ad
ditional information.
[ 50.026] (EE)
[ 50.072] (EE) Server terminated with error (1). Closing log file.

This is not a support forum so you should log a bug.

However before you do that it might be helpful to see if your system automatically reported the crash. Go to https://errors.ubuntu.com/user/ID where ID is the contents of /var/lib/whoopsie/whoopsie-id

If you find the crash was reported there then please include a link to what you found in the bug report.