GridFieldAddNewButtons template could not be found

<%- if @topic_view.topic.tags.present? %>
<%= t 'js.tagging.tags' %>: <%- @topic_view.topic.tags.each do |t| %> <%= t %> <%- end %>
<% end %>

I am using Silverstripe 4.4.3, attempting to upgrade from Silverstripe 3.

When I go into the CMS settings, I get the error;

None of the following templates could be found: GridFieldAddNewButton in themes "Array ( [0] => silverstripe/admin:cms-forms [1] => $default ) "

GridFieldAddNewButton and its template exist in silverstripe-framework as one of my vendor modules. I have built and flushed many times, which present no errors, but still get this error when I go to CMS settings. As GridFieldAddNewButton is part of Silverstripe, and not something of mine, I am unsure of how to rectify this problem, or even what this problem is.