CFA is a new Windows Defender anti-ransomware feature, and if you don’t feel that you need ransomware protection, then you can just follow the steps in this article to turn off CFA:
https://support.microsoft.com/en-ph/help/4046851/windows-10-controlled-folder-access-windows-defender-security-center
However, that Microsoft article is purporting to tell you how to:
“Add an app to the list of safe or allowed apps to prevent them from being blocked.”
When in fact it's only providing the steps for turning off CFA – which will allow your friendly apps access to your folders to be sure; but will also allow access for any unfriendly apps, malware, ransomware, or data wipers
– so it’s important to understand how logically distorted this particular article is. The Microsoft article that actually describes how to allow a blocked app through CFA is right here:
https://support.microsoft.com/en-us/help/4012987/windows-10-virus-threat-protection-windows-defender-security-center
When you see one of these Unauthorized Changes Blocked notifications; follow these simple steps to allow the program through
Controlled Folder Access:
1. Click on the notifications icon at the far right in the taskbar.
2. Write down the file path provided in the notification.
3. Click on the notification, and then on the Add button (+).
4. Navigate to the file identified in the notification, and then select and “open” it.
The file path in the Unauthorized Changes Blocked notification tends to be truncated – although there’s usually enough of it there to locate the app without any trouble if you just assume that it’s in the Program Files or Program Files
(x86) directory. If the file path is truncated to the point where you can’t locate the blocked app in the file-picker dialog; then open
Event Viewer; navigate to the Windows Defender Operational
log; and locate the blocking event (Event ID 1123):
1. Right-click on the Start button and select Event Viewer.
2. Navigate to Applications and Services
> Microsoft > Windows
> Windows Defender > Operational
3. Filter for (or just look for): Event ID
1123
Generally speaking, CFA should be turned off whenever you’re installing any new application, and then turned back on again once the installation is complete.
More information is availabe here:
https://answers.microsoft.com/en-us/protect/forum/protect_defender-protect_scanning-windows_10/windows-defender-is-blocking-too-much-saying-it/83a1d803-c687-4ddc-800b-5bb53c6151d1
If CFA starts blocking apps when you haven’t enabled it, then this might be the effect of a compatibility bug that seems to be activating CFA in the presence of some third-party AV apps. In this case, the first thing to try would be disabling the third-party
AV to see if this activates Windows Defender. If so, then toggle CFA on, and then back off again – and then enable the third-party AV in order to turn Defender back off. If that doesn’t work, then you’ll probably have to uninisall and then reinstall the third-party
AV app.
Additionally, some third-party AV apps that are capable or running in tandem with Defender (in its real-time mode) might cause problems with CFA. For example, we’re not sure if the anti-exploit protection packaged with Malwarebytes Premium is fully
compatible with Windows Defender’s CFA.
If CFA is acting erratically in the absence of any third-party AV app, then follow these troubleshooting steps
1. Remove any undetected malware by scanning with several third-party malware-removal apps, starting with Malwarebytes Free:
https://answers.microsoft.com/en-us/protect/forum/protect_other-protect_scanning-windows_other/list-of-malware-removal-tools/d824b9af-ebd8-4c47-94e2-8ee6c544c100
2. Remove any antimalware remnants by running the cleanup utilities for any preinstalled or previously installed AV apps:
https://answers.microsoft.com/en-us/protect/forum/protect_other-protect_start-windows_other/list-of-anti-malware-product-removal-tools/2bcb53f7-7ab4-4ef9-ab3a-6aebfa322f75
3. Run the standard Windows 10 system integrity checks:
https://answers.microsoft.com/en-us/windows/forum/windows_10-update/system-file-check-sfc-scan-and-repair-system-files/bc609315-da1f-4775-812c-695b60477a93
GreginMich