JMWE 6.4.0 brings the following improvements and bug fixes:

Improvements

The Jira Service Management (formerly Jira Service Desk) request "channel" is now available from the Issue interface as the channel property
The Organizations field of Jira Service Management requests can now be set by organization name in addition to organization ID
Emails sent by the Email Issue(s) Post-Function now include an "In-Reply-To" header
The Set Field Value Post-function now support the "run as" option
The Comment [Related] Issues post-functions now always add the sd.public.comment comment property, even for public comments
The Email Issue post-function now ignores recipients without an email address instead of raising an error
The Transition related issues post-function now includes an option to trigger the WorkflowManualTransitionExecutionEvent event
Groovy scripting: a new DateOnly class extends the Date class and allows creating date-only values, which can be created in a user's time zone. This is useful to set fields like the Due Date field.

And bug fixes

[JMWE-838] - java.lang.NoClassDefFoundError exception while testing or running a Groovy script
[JMWE-881] - Transition current issue should not have a "workflow name" column in the transition table
[JMWE-886] - Cannot set Customer Request Type by name after changing project key
[JMWE-890] - the setFieldValue method can only modify one field on jqlSearch results