Basic filter step not working in API provider integration

When using an API provider integration I can not use basic filter step to access the given request body properties or parameters.

When adding the filter step on an API provider operation the property dropdown select is empty although the request has body properties and parameters defined. The properties should be filled by the syndesis-server.

In the logs I only see:

2019-10-08 13:57:00.716  WARN [-,f1aa5c0db233bb71,f1aa5c0db233bb71,false] 1 --- [  XNIO-3 task-5] i.s.s.inspector.JsonSchemaInspector      : Unable to parse the given JSON schema, increase log level to DEBUG to see the schema being parsed