NoMethodError in Collections#show

Showing /app/app/views/collections/_article.html.slim where line #10 raised:

undefined method `name' for nil:NilClass
Extracted source (around line #10):
8
9
10
11
              
.large-9.small-6.columns.end
h2 = link_to article.title, article_path(article.slug)
span.author = link_to article.author.name, user_path(article.author, anchor: 'artigos')
span.comments-count data-slug=article.slug

Trace of template inclusion: app/views/collections/show.html.slim

Rails.root: /app

Application Trace | Framework Trace | Full Trace

Request

Parameters:

{"slug"=>"deixa-que-eu-faco"}

Response

Headers:

None