Selecting a different OS from the dropdown menu does not appear to actually do anything. The expected behavior is the UI would enumerate the BP Launcher installation file(s) for the selected target OS.
Found multiple issues created in the process of refactoring jQuery code to the equivalent Javascript code.
There were calls to getElementById() but the desired elements were identified by their class names.
The selector in the calls to getElementByClass() included a period ('.') character which does match in jQuery code, but does not match in Javascript code.
The return value of getElementsByClass() is an array and not an iterable Object collection. Iterating through the elements returned requires a for/next loop or similar construct to access each element returned.
Selecting a different OS from the dropdown menu does not appear to actually do anything. The expected behavior is the UI would enumerate the BP Launcher installation file(s) for the selected target OS.