For Pier-Seaside, several methods have text like PRMenuRenderer>>visitInternalLink: have code that raises a message-not-understood for #parameterAt..., like:
link parameterAt: 'class' put: (aLink parameterAt: 'class' ifAbsent: [ String new ]) ...
Its odd that this sort of thing has been around since Pier 3.0. A straight-forward solution is to replace this with parameters at, since this variable is defined in PRReference (defined as part of Pillar). It seems direct to add it to the extension Pier-Model.