Provide as much info as you can in the body: versions of Ruby, Rails, and will_paginate, together with your code that triggered the issue and any stack traces.
If the problem is with page links, include related routes from your app.
If you can, run bundle install --without mysql:pg and bundle exec rake in the will_paginate directory. Copy the output if there are failing tests. If your problem is with MySQL or Postgres specifically, remove their name from the --without list for bundle install.