C++ class in blueprint project

Its saying i need to download “Windows SDK v8.1” in order to create the class, is it really needed?
because i have windows SDK version 10

In my experience, you do need it for the time being, as I believe the engine still targets Windows 8.1 (I could be wrong though.) Typically installing the windows 8.1 sdk solves most issues.

thanks man i contacted EPIC ill see what they will advise me to do