Version 4.1.77 fixes a nasty bug that crept in at v4.1.72. The symptoms of this bug were that Glade would crash when opening any layout, *unless* the LSW was already open. As the .gladerc setting file controls whether the LSW is shown on startup, some users did not experience this problem; new users did.
Please update to 4.1.77 asap and discard any versions 4.1.72-76.