about packing win64

[ERROR: Could not find NetFxSDK install dir; this will prevent SwarmInterface from installing. Install a version of .NET Framework SDK at 4.6.0 or higher.]

I have installed the latest version of SDK, but still reported an error. How should I solve it?

Do you have only 1 instance of UE4 editor opened?
I had this kinda problem, and it helped me. I have also tried to reboot my PC