TempalteData-provided parameter list in template editor is not scrollable.
For example, try adding [[pl:Template:Okręt infobox]] to any article there.
Confirmed on latest versions of Firefox and Opera.
Screenshot: http://i.imgur.com/e3VSqVs.png
Version: unspecified
Severity: major
See Also:
https://bugzilla.wikimedia.org/show_bug.cgi?id=51672