The 4.1.0 release includes the following backwards incompatible changes.
Ontologies
http://fedora.info/definitions/v4/indexing#
"Indexable" predicate
| Warning |
|---|
| From 4.0.0: indexing#indexable |
| Tip |
|---|
| To: 4.1.0: indexing#Indexable |
Full diff of changes to the ontologies between 4.0.0 and 4.1.0