Impossible to create new case Type

[larnoult]

Clicking on the button "Nouveau case type" (from the manage workflow page wp-admin/admin.php?page=CiviCRM&q=civicrm%2Fworkflow%2Fa&case_type_category=1&p=al#/list) redirects to a subscription form page on our install.
https://www.parlemonde.org/adherer-a-lassociation-par-le-monde/#/caseType/new
A workaround is to duplicate existing case type (which works).

Another workaround is to use the API explorer :-)