All searches returning error 500: incompatible character encodings: UTF-8 and ASCII-8BIT

Hi.
Probably (but not 100% sure) since the upgrade to 10.5 (omnibus on ubuntu16) we’re unable to perform searches on several repositories.
In the logs I found the following:

Encoding::CompatibilityError (incompatible character encodings: UTF-8 and ASCII-8BIT):
  app/views/layouts/application.html.haml:9:in `_app_views_layouts_application_html_haml__106264521056078181_70264416806300'
  app/views/layouts/search.html.haml:4:in `_app_views_layouts_search_html_haml__424264017246152946_70264420652720'
  lib/gitlab/i18n.rb:47:in `with_locale'
  lib/gitlab/i18n.rb:53:in `with_user_locale'
  app/controllers/application_controller.rb:325:in `set_locale'
  lib/gitlab/middleware/multipart.rb:95:in `call'
  lib/gitlab/request_profiler/middleware.rb:14:in `call'
  lib/gitlab/middleware/go.rb:17:in `call'
  lib/gitlab/etag_caching/middleware.rb:11:in `call'
  lib/gitlab/middleware/read_only.rb:31:in `call'
  lib/gitlab/request_context.rb:18:in `call'
  lib/gitlab/metrics/requests_rack_middleware.rb:27:in `call'

How can I fix? Is there a reindex or something which can restore search functionality?

thanks

… just found the issue on gitlab.com!