The approach I received from VMware support was to manually move my workflows etc. from 7.5 to 7.6 instead of upgrading, which was why I researched the following solution.
However be warned: This is not an official supported solution, while I don't see any issues with it I can't guarantee that you are still supported afterwards.
Resolution:
- Login at the console or via SSH into your vRealize Orchestrator appliance with root credentials.
- Stop the Orchestrator Service
- service vco-server stop
- Remove all lucene log files
- rm -rf /var/log/vco/app-server/scripting.log_lucene*
- Start the orchestrator service
- service vco-server start
- Logout from the console / ssh session
Everything should be good again.