freemarker.core.InvalidReferenceException: The following has evaluated to null or missing:
==> actor.parent  [in template "util.ftl" at line 120, column 15]

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Tip: It's the step after the last dot that caused this error, not those before it.
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Tip: If the failing expression is known to 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)??
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FTL stack trace ("~" means nesting-related):
	- Failed at: #if (actor.parent == parent && actor...  [in template "util.ftl" in macro "get_grup" at line 120, column 9]
	- Reached through: @get_grup actors=assignment.event.act...  [in template "orar_complet.ftl" at line 59, column 13]
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