The FreeMarker templates appear to work differently between 9.10 and 10.1. Document properties are dereferenced differently.
The following works in 9.10, but is broken in 10.1:
The following works in 10.1, but is broken in 9.10:
To reproduce, change the pom.xml:parent/version to one of 9.10 or 10.1 in the project:
And modify nuxeo-orbeon-rest/src/main/resources/skin/obsearch2.ftl with one of the above examples to reproduce success/failure with mvn test