with redmine 4.0.4 stable encount following problem
undefined method alias_method_chain' for IssuesController:Class Did you mean? alias_method (NoMethodError) /opt/redmine/plugins/redmine_issues_tree/lib/redmine_issues_tree/issues_controller_patch.rb:5:inblock in '
/var/lib/gems/2.5.0/gems/activesupport-5.2.3/lib/active_support/concern.rb:122:in class_eval' /var/lib/gems/2.5.0/gems/activesupport-5.2.3/lib/active_support/concern.rb:122:inappend_features'
/var/lib/gems/2.5.0/gems/require_patch-0.3.3/lib/require_patch.rb:30:in include' /var/lib/gems/2.5.0/gems/require_patch-0.3.3/lib/require_patch.rb:30:inblock in require_patch'
/var/lib/gems/2.5.0/gems/require_patch-0.3.3/lib/require_patch.rb:23:in each' /var/lib/gems/2.5.0/gems/require_patch-0.3.3/lib/require_patch.rb:23:inrequire_patch'
/opt/redmine/plugins/redmine_issues_tree/init.rb:17:in block in <top (required)>' /var/lib/gems/2.5.0/gems/activesupport-5.2.3/lib/active_support/callbacks.rb:426:ininstance_exec'
Looks like you use master branch. Please, take a look at ReadMe and use branch according to your Redmine version. In your case this is 4.0.*. And all will be fine.
with redmine 4.0.4 stable encount following problem
undefined method'
/var/lib/gems/2.5.0/gems/activesupport-5.2.3/lib/active_support/concern.rb:122:in
alias_method_chain' for IssuesController:Class Did you mean? alias_method (NoMethodError) /opt/redmine/plugins/redmine_issues_tree/lib/redmine_issues_tree/issues_controller_patch.rb:5:in
block inclass_eval' /var/lib/gems/2.5.0/gems/activesupport-5.2.3/lib/active_support/concern.rb:122:in
append_features' /var/lib/gems/2.5.0/gems/require_patch-0.3.3/lib/require_patch.rb:30:ininclude' /var/lib/gems/2.5.0/gems/require_patch-0.3.3/lib/require_patch.rb:30:in
block in require_patch' /var/lib/gems/2.5.0/gems/require_patch-0.3.3/lib/require_patch.rb:23:ineach' /var/lib/gems/2.5.0/gems/require_patch-0.3.3/lib/require_patch.rb:23:in
require_patch' /opt/redmine/plugins/redmine_issues_tree/init.rb:17:inblock in <top (required)>' /var/lib/gems/2.5.0/gems/activesupport-5.2.3/lib/active_support/callbacks.rb:426:in
instance_exec'