Since Jira 8.19.0 some methods have been moved from the TemplateIssue class to a parent class (GenericIssueWrapper). As part of this refactor a method was dropped which could affect existing custom Template Sets created through JEMH that depend on the $issue object.
Dropped Methods
getCustomField(String Id)
Templates relying on this method will not be able to retrieve Custom Fields directly from the $issue object. As a workaround we recommend replacing any uses of this method with $customFieldManager.getCustomFieldObject(String id) . See:
Before Jira 8.19.0
#set($myCustomField = $issue.getCustomField("customfield_10100"))
After Jira 8.19.0
#set($myCustomField = $customFieldManager.getCustomFieldObject("customfield_10100"))
Documentation
The following documentation shows the available methods available for the TemplateIssue class, before and after the API change.
Before Jira 8.19.0
After Jira 8.19.0
TemplateIssue:
GenericIssueWrapper