Route error after publishing theme

[fdriesner]

Installed spree_themes
gem 'vinsol_spree_themes', github: 'vinsol-spree-contrib/spree_themes', branch: 'master'

 'ruby-2.3.4'
 gem 'spree', '~> 3.4.0'
 gem 'spree_auth_devise', '~> 3.3'
 gem 'spree_gateway', '~> 3.3'

Getting route error after publishing either one
https://github.com/vinsol-spree-contrib/theme-BigShop/archive/3-3-bump.zip
https://github.com/vinsol-spree-contrib/theme-ClassicWhite/archive/3-3-bump.zip

ActionView::Template::Error (No route matches {:action=>"show", :controller=>"sp
ree/admin/themes_preview", :theme_id=>nil}, possible unmatched constraints: [:th
eme_id]):
    18:   <div class="alert alert-preview" role="alert">
    19:     <h4 class="text-center">
    20: <%= Spree.t('warnings.preview_mode_message') %>
    21:       <%= link_to 'X', admin_theme_preview_path(params[:theme]), method: :delete, class: 'pull-right' %>
    22:     </h4>
    23:   </div>
    24: <% end %>

app/views/spree/layouts/spree_application.html.erb:21:in `_62df21b47e640970cf406
a5536f93374'

Routes:

Helper	HTTP Verb	Path	Controller#Action
spree_path		/	Spree::Core::Engine
state_change_admin_theme_path	PATCH	/admin/themes/:id/state_change(.:format)	spree/admin/themes#state_change
download_admin_theme_path	PATCH	/admin/themes/:id/download(.:format)	spree/admin/themes#download
upload_admin_themes_path	POST	/admin/themes/upload(.:format)	spree/admin/themes#upload
admin_theme_templates_path	GET	/admin/themes/:theme_id/templates(.:format)	spree/admin/themes_templates#index
	POST	/admin/themes/:theme_id/templates(.:format)	spree/admin/themes_templates#create
new_admin_theme_template_path	GET	/admin/themes/:theme_id/templates/new(.:format)	spree/admin/themes_templates#new
edit_admin_theme_template_path	GET	/admin/themes/:theme_id/templates/:id/edit(.:format)	spree/admin/themes_templates#edit
admin_theme_template_path	PATCH	/admin/themes/:theme_id/templates/:id(.:format)	spree/admin/themes_templates#update
	PUT	/admin/themes/:theme_id/templates/:id(.:format)	spree/admin/themes_templates#update
admin_theme_preview_path	GET	/admin/themes/:theme_id/preview(.:format)	spree/admin/themes_preview#show
	DELETE	/admin/themes/:theme_id/preview(.:format)	spree/admin/themes_preview#destroy
admin_themes_path	GET	/admin/themes(.:format)	spree/admin/themes#index
admin_theme_path	DELETE	/admin/themes/:id(.:format)	spree/admin/themes#destroy

[himanshumishra31]

Hi @fdriesner

Did you add sprockets-helper gem in your gemfile??
If not please add gem 'sprockets-helpers', '~> 1.2.1' to your gemfile and bundle

I hope this works.

Thank you