Elastic Instance "Instances schedule" section throws an "Internal server error" when we hit Save

Version: 6.2.5
Build: 60212
Build Date: 06 Dec 2017

Request information:
Request URL: http://bambURL/admin/elastic/schedule/saveElasticInstanceSchedule.action
Scheme: http
Server: bamboo.gwynniebee.com
Port: 80
URI: /admin/elastic/schedule/saveElasticInstanceSchedule.action
Context path:
Servlet path: /admin/elastic/schedule/saveElasticInstanceSchedule.action
Path info:
Query string:
Stack Trace:

java.lang.NullPointerException
	at com.atlassian.bamboo.ww2.actions.admin.elastic.schedule.ConfigureElasticInstanceSchedule.save(ConfigureElasticInstanceSchedule.java:181)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at ognl.OgnlRuntime.invokeMethod(OgnlRuntime.java:894)
	at ognl.OgnlRuntime.callAppropriateMethod(OgnlRuntime.java:1539)
	at ognl.ObjectMethodAccessor.callMethod(ObjectMethodAccessor.java:68)
	at com.opensymphony.xwork2.ognl.accessor.XWorkMethodAccessor.callMethodWithDebugInfo(XWorkMethodAccessor.java:96)
	at com.opensymphony.xwork2.ognl.accessor.XWorkMethodAccessor.callMethod(XWorkMethodAccessor.java:88)
	at ognl.OgnlRuntime.callMethod(OgnlRuntime.java:1615)

2018-01-03 01:22:13,775 ERROR [http-nio-8085-exec-23] [runtime] Error executing FreeMarker template
FreeMarker template error:
The following has evaluated to null or missing:
==> stack.findString(parameters.listValue)  [in template "template/aui/radiomap.ftl" at line 27, column 38]

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Tip: If the failing expression is known to be legally refer to something that's sometimes null or missing, either specify a default value like myOptionalVar!myDefault, or use [#if myOptionalVar??]when-present[#else]when-missing[/#if]. (These only cover the last step of the expression; to cover the whole expression, use parenthesis: (myOptionalVar.foo)!myDefault, (myOptionalVar.foo)??