Redmine

I have two queries. Both are using a custom field where users of redmine are linked to issues. (not as assignee, but associated)
On one I get this error in my logs:

custom field 61 is the one making trouble

Started GET "/projects/computer/issues?utf8=%E2%9C%93&set_filter=1&f%5B%5D=status_id&op%5Bstatus_id%5D=*&f%5B%5D=tracker_id&op%5Btracker_id%5D=%3D&v%5Btracker_id%5D%5B%5D=14&f%5B%5D=&c%5B%5D=subject&c%5B%5D=cf_58&c%5B%5D=status&c%5B%5D=cf_57&c%5B%5D=cf_59&c%5B%5D=cf_64&c%5B%5D=cf_63&c%5B%5D=cf_62&c%5B%5D=cf_53&c%5B%5D=cf_61&group_by=cf_46&t%5B%5D=" for 192.168.2.167 at 2018-05-23 15:03:53 +0200
Processing by IssuesController#index as HTML
  Parameters: {"utf8"=>"✓", "set_filter"=>"1", "f"=>["status_id", "tracker_id", ""], "op"=>{"status_id"=>"*", "tracker_id"=>"="}, "v"=>{"tracker_id"=>["14"]}, "c"=>["subject", "cf_58", "status", "cf_57", "cf_59", "cf_64", "cf_63", "cf_62", "cf_53", "cf_61"], "group_by"=>"cf_46", "t"=>[""], "project_id"=>"computer"}
  Current user: hebold (id=61)
  Rendered queries/_filters.html.erb (12.9ms)
  Rendered queries/_columns.html.erb (1.5ms)
  Rendered issues/_list.html.erb (273.2ms)
  Rendered issues/index.html.erb within layouts/base (292.2ms)
Completed 500 Internal Server Error in 442ms (ActiveRecord: 84.3ms)

ActionView::Template::Error (undefined local variable or method `item' for #<#<Class:0x00563c5e6eae88>:0x007f128233ed70>):
    28:   <% end %>
    29:   <tr id="issue-<%= issue.id %>" class="hascontextmenu <%= cycle('odd', 'even') %> <%= issue.css_classes %> <%= level > 0 ? "idnt idnt-#{level}" : nil %>">
    30:     <td class="checkbox hide-when-print"><%= check_box_tag("ids[]", issue.id, false, :id => nil) %></td>
    31:     <% query.inline_columns.each do |column| %>
    32:     <%= content_tag('td', column_content(column, issue), :class => column.css_classes) %>
    33:     <% end %>
    34:   </tr>
  app/helpers/queries_helper.rb:132:in `block in column_content'
  app/helpers/queries_helper.rb:132:in `collect'
  app/helpers/queries_helper.rb:132:in `column_content'
  app/views/issues/_list.html.erb:31:in `block (3 levels) in _app_views_issues__list_html_erb__2826051833959946854_47408662523580'
  app/views/issues/_list.html.erb:30:in `each'
  app/views/issues/_list.html.erb:30:in `block (2 levels) in _app_views_issues__list_html_erb__2826051833959946854_47408662523580'
  app/helpers/issues_helper.rb:56:in `block in grouped_issue_list'
  app/helpers/issues_helper.rb:30:in `block in issue_list'
  app/helpers/issues_helper.rb:26:in `each'
  app/helpers/issues_helper.rb:26:in `issue_list'
  app/helpers/issues_helper.rb:41:in `grouped_issue_list'
  app/views/issues/_list.html.erb:16:in `block in _app_views_issues__list_html_erb__2826051833959946854_47408662523580'
  app/views/issues/_list.html.erb:1:in `_app_views_issues__list_html_erb__2826051833959946854_47408662523580'
  app/views/issues/index.html.erb:74:in `_app_views_issues_index_html_erb__1941775417574223512_47408641264820'
  app/controllers/issues_controller.rb:76:in `block (2 levels) in index'
  app/controllers/issues_controller.rb:75:in `index'
  lib/redmine/sudo_mode.rb:63:in `sudo_mode'