Support for redmine 4.1?

[ilovetacos]

Hi, I wanted to ask if there is a chance to get this plugin working for redmine 4.1 I get this error:

  Rendering plugins/projects_tree_view/app/views/projects/index.html.erb within layouts/base
  Rendered plugins/projects_tree_view/app/views/projects/index.html.erb within layouts/base (4.5ms)
Completed 500 Internal Server Error in 32ms (ActiveRecord: 7.2ms)

ActionView::Template::Error (undefined method `sort_by' for nil:NilClass):
    33:   <tbody>
    34:     <% ancestors = [] %>
    35:     <% plevel = 0 %>
    36:     <% project_tree(@projects) do |project, level| %>
    37:       <% project_id = "%04d" % project.id %>
    38:       <%  (plevel - level).times { ancestors.pop } if (level < plevel) %>
    39:       <% has_children = !project.children.empty? %>

app/models/project.rb:876:in `project_tree'
app/helpers/application_helper.rb:559:in `project_tree'
plugins/projects_tree_view/app/views/projects/index.html.erb:36:in 
`_plugins_projects_tree_view_app_views_projects_index_html_erb__1452158997881093995_47001345313440'

My environment:

Environment:
  Redmine version                4.1.1.stable
  Ruby version                   2.5.5-p157 (2019-03-15) [x86_64-linux-gnu]
  Rails version                  5.2.4.2
  Environment                    production
  Database adapter               Mysql2