I am having the same issue as the poster of the original thread, however we are using Jira 7.1 and cannot use SOAP. I have attached a screenshot of the relevant information, however, in short I am trying to fill custom field 11931 by entering

custom_field11931:11255

into Extra Attributes as described in the comments on the linked thread. This is the code that is working on JIRA issues that were created prior to our migration to 6.1.9 (and also prior to our upgrade to JIRA 7.1). THe screenshot shows the REST API calls that should confirm that that is the correct ID, however the step continues to fail with the following error message:

19:29:46,129 ERROR - Unknown custom field type OPTION
19:29:46,292 INFO - Executing post-execute action...
19:29:46,292 ERROR - Step 'master>Scheduled Job Failure - JIRA ticket' is failed.
    com.pmease.quickbuild.plugin.tracker.core.TrackerException: RestClientException{statusCode=Optional.of(400), errorCollections=[ErrorCollection{status=400, errors={customfield_11931=Could not find valid 'id' or 'value' in the Parent Option object.}, errorMessages=[]}]}
        at

What am I doing wrong? Does this really require an upgrade to 6.1.12 or is this workaround supposed to work if below 6.1.12?