The OTO ontology (OBOFoundry/OBOFoundry.github.io#2650) dashboard check reports no issues regarding definitions, yet the ontology contains no definitions at all. Could this be due to the lack of any class declarations? Here's how classes are given in the OWL file:
<Declaration>
<Class IRI="#Development_Feedback"/>
</Declaration>
<Declaration>
<Class IRI="#Gender"/>
</Declaration>