HoI 4 - Starting a new game causes crash to desktop since installing no step back.

[Stone Fox]

Description of issue
Starting a new game causes crash to desktop since installing no step back.

Game Version
v.1.11.4.e26e (b22c)

Enabled DLC
Together for Victory, Death or Dishonor, Waking the Tiger, Man The Guns, La Resistance, Battle for the Bosporus, No Step Back

Do you have mods enabled?
No

Description
Recently purchased Hoi4, worked fine. I've never used any mods. Decided to by the one DLC I hadn't got on sale, NSB, and now the game can't start a campaign.
The menu works fine, starting a game crashes to desktop while initializing.
I've tried removing the files in the user folder and verifying steam file integrity.
Disabling cloud saving.
I've also tried completely uninstalling and removing all trace of the game and reinstalling, still doesn't work.
At this point I've paid the best part of £50 for a game that won't work ,vanilla, on a fresh install.

I have also since noticed that trying to change my graphics setting produces an error saying it can't write to the settings file. (see screenshot)

Steps to Reproduce
Starting a new game causes crash to desktop since installing no step back.

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[Stone Fox]

I've resolved the minor part of the settings file by excluding the game directories from Avast scans. I still can't play a game, and even the menu randomly crashes to desktop.
*Edit to add, not fixed. As soon as it'd CTD's the issue with writing to the save file restarted.

 

[SchwarzKatze]

Completely turn off Avast protection and try again? Avast and AVG seem to have bones to pick with Paradox games.

 

[Stone Fox]

I've got 200 hours in the game, it only stopped working when I installed No Step Back. Avast hadn't caused *any* issues before, but I'll try.

 

[Stone Fox]

Turning off Avast protection completely resolves it.

But why does this only happen after installing NSB? How do I resolve this? I already exempt all the Hoi4 folders from Avast scans.

 

[SchwarzKatze]

Turning off Avast protection completely resolves it.

But why does this only happen after installing NSB? How do I resolve this? I already exempt all the Hoi4 folders from Avast scans.

Does "all the HoI4 folders" include Documents\Paradox Interactive\Hearts of Iron IV? It's where most of the non-static files like settings, saves, and caches are stored.
As for why, maybe Avast doesn't have the updated version of the game exe in their whitelist?