of note - after repeatedly testing this to find the reason behind the inconsistency - I didn't find any.
I did find however that the code does not always break immediately during login - but after pressing a number of the buttons on the UI - I can get the code to break at that same line 575 in component-manager.js -
SelectMenuFacade.prototype.get_selectedMenuItem = function (c) {
return c.val().trim();
with the error - cannot read property trim() of null ... ( of note this may be a timing thing - that the UI's are always closing or opening at the time this error gets thrown - and - if the components don't exist - I could see the use case where this error would present itself..... and might work on some days & times (when the UI's took more or less time to present themselves - and the 'expected' behavior persistent...)...
Can I somehow 'fix' this function by overwriting it with my own function that has an error trap - where if c.val() is null - it doesn't try to trim it - and only returns undefined ??