I installed ExtFS on my PC in order to access files on a Linux external drive.
At the end of the installation an error was displayed stating that Windows had blocked the installation of a digitally unsigned driver (Dokan Filesystem Driver)
Unfortunately i have to tell you that your are not alone
I have the same problem on my PC running Windows 10 Pro 64bit, Version 1709, Build 16299.98
ExtFS Version 4.3.852
This seems to be caused by the file dokan.sys located under c:\windows\system32\drivers - so if you open up a command prompt with administrator privileges and type "net start dokan" you´ll get an error message.
The only workaround is to startup and disable Windows 10s requirement for signed drivers