There is a plugin to create tenants in pentaho 5.0.1
Recently when the same plugin, after updating the dependencies to 6.1-SNAPSHOT, is unable to create tenant.

createTenant throws an exception....and not able to create folders.
When tried to call createTenant second time...throws an exception "AlreadyExists"

I filed an issue https://github.com/pentaho/pentaho-platform/issues/2733

I debugged the exception is being thrown from jackrabbit-core 2.10.1

Exception stack trace,logs are in the github issue link