[4.7] Critical bug - Opening any UMG widget asset, causes crash.

This is the range of latest commit I pulled from github:

16fffaa…c0cff5a

Reproduction is very simply. Create new UMG widget asset, try to open it… Crash.

Edit:

else
{
	ensureMsgf(false, TEXT("Unknown UI selection state in FBlueprintEditor::RefreshEditors"));
}

This is line at which it crashes in BlueprintEditor.cpp.

Edit:
Not sure if this is important.
But build game in debug mode, and run from visual studio in debug mode.

Hello iniside,

Thank you for your information and your time. Please keep in mind that the latest branch on github is a live branch and is considered highly unstable and could potentially contain many errors.

Make it a great day