AvastSvc stops intermittently with an error

My AvastSvc fails several times a day, seemingly at random and has done for several weeks.
I’ve uninstalled Avast Antivirus, downloaded it fresh and reinstalled it with no improvement to the problem.
I’ve attached a screenshot of the error details which follow:

Faulting application name: AvastSvc.exe, version: 12.3.3154.0, time stamp: 0x57b5c39d Faulting Module name: ntdll.dll, version: 10.0.10586.306, time stamp: 0x571afb7f Exception code: 0xc0000374 Fault offset: 0x000dc7c9 Faulting process ID: 0x124 Faulting application start time: 0x01d2758e30234c53 Faulting application path: F:\Program Files\AVAST Software\Avast\AvastSvc.exe Faulting module path: F:\WINDOWS\SYSTEM32\ntdll.dll Report ID: c138a6ee-6243-43db-9181-63ace19b1ce1 Faulting package full name: Faulting package-relative application ID:

The service restarts perfectly fine when I resolve the problem in the UI, but I actively have to open the UI and restart the service if I happen to notice it’s not running.

I’ve submitted a support ticket to Avast but they don’t seem to be prepared to support their own software unless I buy Premium features that I don’t want. If they do decide to assist on the ticket, I’ll update this thread accordingly.

EDIT

I’m running Windows 10 Pro (no service pack that I’m aware of) and I don’t have any other security software running at all outside of Windows Firewall. Not even BitDefender.

What OS/SP ?
What exact version of avast ?
Is there any other security (related) software installed ? (or was there)

Sorry for being so light on relevant information. I’ve updated the post but to sum up here:

Windows 10 Pro (no SP) and there’s no other security software running.

Repair Avast:
Control Panel> Program and Features (Add/remove program)>Select Avast> Select Repair. Reboot when completed
https://www.avast.com/faq.php?article=AVKB204
If Repair doesn’t fix the problem, try the following:
Clean Install of Avast:
https://goo.gl/4Ptzkf

Avast recommended a full reinstall on twitter so I started with that in the first place.