There is an addon (MSW?) with a too old version of LAM2. Go and search for LibAddonMenu files and replace older once with those of a recent updated addon.
A good one should look like this:
Code:
-- LibAddonMenu-2.0 & its files © Ryan Lakanen (Seerah) --
-- Distributed under The Artistic License 2.0 (see LICENSE) --
------------------------------------------------------------------
--Register LAM with LibStub
local MAJOR, MINOR = "LibAddonMenu-2.0", 18
local lam, oldminor = LibStub:NewLibrary(MAJOR, MINOR)
...
/Edit 1. MSW is MyStatusWindow, right? This addon has LAM2 r14.