In the Viewer Libraries path under Preferences/Viewer/Plugins/MultiView, manually pasting the path to the DLL folder causes Preferences UI to freeze completely—left or right mouse clicks become unresponsive.
This freeze occurs whether you enter the actual absolute path or an alias path.
However, if you click the folder icon on the right side of the path bar and navigate step by step to select that folder, the freeze does not happen.
Additionally, pasting a folder path that does not contain the dll does not trigger the freeze.
Clicking the close button (the "X" next to "Preferences") in the top‑right corner of the main window to exit preference editing mode, also has no effect—the UI remains frozen and cannot be closed.