Well the library team can not support any further v4 release. (We already moved to the new repos.)So if there really is a 4.0.8 release it will get the 4.0.7 libs.
A signed Nightly 12/12/17 put up last night Let's get testing
And search tree in Symbol Library Editor, sometimes works, sometimes not...
Look at the mailing list. There seem to be platform specific problems. I think reporting a bug about your specific behavior might be a good idea.