This error has been encountered on ODF, but can be reproduced with exhaustive plugin of template web. 

(To reproduce it on web template : rename main views of edition type by "default-edition" on parent, child and exhaustive types)
No metadata set for edition with name 'main' nor fallback metadata set with name 'main' and content type(s) 'org.ametys.plugins.odf.Content.subProgram'java.lang.IllegalArgumentException: No metadata set for edition with name 'main' nor fallback metadata set with name 'main' and content type(s) 'org.ametys.plugins.odf.Content.subProgram'    at org.ametys.cms.contenttype.ContentTypesHelper.getMetadataSetWithFallback(ContentTypesHelper.java:763)
    at org.ametys.cms.content.GetMetadataSetDefAction.content2Json(GetMetadataSetDefAction.java:207)