Getting error when trying to set default value in Issue Picker for Jira 8.16.0 and above

This problem is occurring in Jira 8.16.0 and above

Steps to Reproduce

1. Create an Issue Picker field
   • Go to Jira Administrator > Manage Apps > ScriptRunner > Fields > Create Script Field > Issue(s) picker
2. Edit the default value
   • While in Script Fields page, click the three-dots of the Issue Picker > Configure Contexts > Edit Default value

Expected Behaviour

The Set Custom Field Defaults page loads fine and able to set default value

This is in Jira 8.15.0

Actual Behaviour

The Set Custom Field Defaults page loads with an error

Workaround

Use Behaviour to set the default value into the Issue Picker
Example code:

def field = getFieldById(getFieldChanged())
def fieldValue = field.getValue()

if (!fieldValue){
	field.setFormValue("QQQ-7")
}