Controlled Folder Access Blocked problem in Windows Defender

Included in that trashy outdated software is the latest release of Visual Studio 2017, IISExpress, and many other Microsoft tools. It seems like Defender could at least check the app's certificate before blocking it.

Actually Mark, If you'll look at the date of the original post in this thread as well as the applications involved, what I stated was likely true for those applications, but as with others who continue to find and abuse this badly outdated question, you've chosen to pile on in a thread that has nothing to do with your own individual problem simply because the title included "Controlled Folder Access blocked".

Since this thread began, even I have experienced a single instance of similar CFA notifications relating to portions of the Internet Explorer browser I'd just recently been using during a browsing session that also included several obvious attacks, since I had been purposefully "browsing dangerously" in order to test other security features of Windows 10.  In my particular case, these notifications only stopped once I completely shut down and rebooted the operating system, since which time they haven't re-appeared.

My experience makes me believe that some of these odd notifications relating to operating system files or those for major applications might relate to either remnants of malicious attacks or other flaky issues with application operation that the CFA components are mistaking for possible malicious ransomware activity.

Based on this, my first recommendation is to try powering down and rebooting Windows 10, making sure that any possible attacks or other problems you might have noticed with the application(s) involved during the most recent sessions have all been resolved as well.  If the application is misbehaving as my Internet Explorer clearly was, it's easily possible that the CFA protection is mistaking this activity as malicious.

If the problem seems more permanent, then I tend to agree with GlenProuty's theory in an earlier post that there may be some form of corruption in either the OS or the application's themselves.  His suggestion to perform a repair upgrade of the OS or possibly a repair of the application itself are both potentially valid methods to try and resolve the problem.

Also, as always it's possible that this situation is somehow being aggravated by the conflicting operation of some other security software installed on the system either currently or in the past which hadn't been completely removed using the manual tools 3rd-party vendors provide for this purpose.

In any case, this thread should have been locked long ago, since it's become a magnet for these seemingly random and confused posts, few of which have had any relation to the original application or problem for which it was begun.

Anyone reading this should, as always, begin your own thread stating only your own specific problems and steps already attempted to fix them.  Just because they may sound similar doesn't mean they have anything to do with what's been discussed here, as the confusion above should clearly display.

Rob