Same Problem every time with Maintained Mods.

[ShadowProwler420]

F10 will cycle through three steps that toggle various UI settings...."Normal" view (any transparency/opacity settings are used), "Full On" (all active/open windows are shown at full view regardless what custom transparency/opacity settins are in place), and "Nothing" (no UI is shown, just game/world graphics).

Try going into the second view mentioned above. Perhaps that will allow you to see the maintained window. Then check the transparency/opacity settings on it. Maybe somehow/someway the settings on the window are being changed (which, I admit, is extremely peculiar....seeing that only one window is being affected and not the whole UI).

/shrug