Visual Studio - "restore" code refactoring error in infobar

Question

I have VS 2017 and in debug encountered a message like this (not my code, had to find it in the internet as i don't have this message any longer)

I've pressed "Enable" and the message has disappeared, but now it affects my debugging as simple assignment operation var a = "something" throws null reference exceptions and my code fails, is there any way to revert the "Enable" action and rollback the changes made by it?

UPD 1:
I tried devenv reset, updating and reinstalling vs, didn't fix the issue

UPD 2:
the issue seems to be more of a cosmetic origin, calling a method with a variable that threw an exception as one of the parameters results in a correct value being passed to the called method

Answer 1

"...is there any way to revert the "Enable" action..."

Disabling Extensions can happen from the Tools -> Extensions and Updates window.

As far as being able to rollback changes made by it, make sure Visual Studio is not synchronizing settings, and do a full uninstall/reinstall.

Synchronization settings are outlined here.

In order to provide more help, I would need to know what extensions are installed.