No page details for pages with many participations

The page details popup does not open on pages with many participations.

I created some participations for a test page and got the following error:

ActionView::Template::Error (No route matches {:action=>"index", :controller=>"pages/participations", :page=>2, :page_id=>1002, :tab=>"permissions"}): 29: - if uparts.total_entries > pagination_size 30: %tr{class: cycle("odd","even")} 31: %td{colspan:'4'}

@azul: do we get the same error for https://we.riseup.net/crabgrass/committees ?

Has been broken for quite a while.