Er trad een fout op tijdens de verwerking van de sjabloon.
The following has evaluated to null or missing:
==> Titel_Verbergen  [in template "20154#20194#676841" at line 116, column 53]

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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)??
----

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FTL stack trace ("~" means nesting-related):
	- Failed at: #if !getterUtil.getBoolean(Titel_Verb...  [in template "20154#20194#676841" at line 116, column 25]
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1<#-- OU Introductie Onderzoek - Contact Professional Programs.ftl, 27-05-2020 --> 
2 
3    <#assign journalArticleLocalService = serviceLocator.findService("com.liferay.journal.service.JournalArticleLocalService") /> 
4    <#assign journalArticle = journalArticleLocalService.getArticle(getterUtil.getLong(groupId), .vars['reserved-article-id'].data) /> 
5    <#assign articlePrimKey = journalArticle.getResourcePrimKey() /> 
6 
7<#-- Site variabelen ophalen om de link naar aanmelden en e-mailen --> 
8    <#assign groupService = serviceLocator.findService("com.liferay.portal.kernel.service.GroupLocalService") /> 
9    <#assign group = themeDisplay.getScopeGroup() /> 
10    <#assign userpics_url = group.getExpandoBridge().getAttribute("base_url_voor_userpics") /> 
11    <#assign sfeerbeeld_url = Sfeerbeeld.getData() /> 
12    <#assign link_contact_formulier = "contact-professional-programs" /> 
13    <#assign Pagina_Koppeling = Pagina_Koppeling.getFriendlyUrl() /> 
14    <#assign Link_Koppeling = Link_Koppeling.getData() /> 
15 
16<#-- Twitter en Facebook URL genereren --> 
17    <#assign Current_URL = request.getAttribute("CURRENT_COMPLETE_URL") /> 
18    <#assign twitter_URL = httpUtil.encodeURL(Current_URL) /> 
19    <#assign facebook_URL = Current_URL /> 
20    <#assign InleidingAsPlainText = Inleiding.getData()?replace("<.*?>","","r") /> 
21    <#assign mailto = "mailto:?subject=" + languageUtil.get(locale, 'GELEZEN_OP_OU_NL') + " " + .vars['reserved-article-title'].data + "&body=" + InleidingAsPlainText + " [" + Current_URL + "]" /> 
22 
23<#-- Contact persoon informatie ophalen --> 
24    <#assign Persoon_Tonen = "false" /> 
25 
26    <#if Persoon.getChild("Persoon_Tonen").getData()=="true"> 
27        <#assign Persoon_Tonen = "true" /> 
28        <#assign Persoon_Gebruikersacroniem = Persoon.getChild("Persoon_Gebruikersacroniem").getData() /> 
29        <#assign Persoon_Naam = Persoon.getChild("Persoon_Naam").getData() /> 
30        <#assign Persoon_Titel = Persoon.getChild("Persoon_Titel").getData() /> 
31        <#if Persoon.Persoon_Gebruikersacroniem.getData() != ""> 
32            <#assign Persoon_Foto_URL = userpics_url + Persoon.Persoon_Foto_Url.getData() /> 
33        <#else> 
34            <#assign Persoon_Foto_URL = Persoon.Persoon_Foto_Url.getData() /> 
35        </#if> 
36        <#if Persoon_Functie?has_content && Persoon_Functie != ""> 
37            <#assign Persoon_Functie = Persoon.Persoon_Functie.getData() /> 
38        </#if> 
39    </#if> 
40 
41<#-- category name --> 
42    <#assign vocLocalService = serviceLocator.findService("com.liferay.asset.kernel.service.AssetVocabularyLocalService") /> 
43    <#assign catLocalService = serviceLocator.findService("com.liferay.asset.kernel.service.AssetCategoryLocalService") /> 
44    <#assign companyGroupId = themeDisplay.getCompanyGroupId() /> 
45    <#assign vocabulary = vocLocalService.getGroupVocabulary(companyGroupId,"Wetenschapsgebied") /> 
46    <#assign vocabularyId = vocabulary.vocabularyId /> 
47    <#assign articleCatNames = catLocalService.getCategoryNames("com.liferay.journal.model.JournalArticle", getterUtil.getLong(articlePrimKey)) /> 
48    <#assign categories = catLocalService.getCategories("com.liferay.journal.model.JournalArticle", getterUtil.getLong(articlePrimKey)) /> 
49    <#assign categoryName = "corporate" /> 
50        <#list categories as category> 
51            <#if category.vocabularyId == vocabularyId> 
52                <#assign categoryName = category.getName() /> 
53                <#assign categoryName = categoryName?replace("\\W", " ", "r")?replace("\\s+", "-", "r")?lower_case /> 
54                <#if categoryName?starts_with("-")> 
55                    <#assign categoryName = categoryName?string[1] /> 
56                </#if> 
57            </#if> 
58        </#list> 
59 
60    <#if locale.toString()?contains("nl_NL")> 
61        <#assign informatiekunde = "Informatiekunde" /> 
62    <#else> 
63        <#assign informatiekunde = "Information science" /> 
64    </#if> 
65    <#assign algemenePagina = false /> 
66 
67    <#assign colorKey = " bg--corporate " /> 
68        <#assign quickFocus = " " /> 
69    <#if categoryName == "cultuurwetenschappen"> 
70        <#assign colorKey = " bg--cw " /> 
71    <#elseif categoryName == "milieu-natuurwetenschappen" || categoryName == "natuurwetenschappen" /> 
72        <#assign colorKey = " bg--nw " /> 
73    <#elseif categoryName == "informatica-en-informatiekunde" || categoryName == "informatica" /> 
74        <#assign colorKey = " bg--inf " /> 
75    <#elseif categoryName == "informatiekunde" /> 
76        <#assign colorKey = " bg--inf " /> 
77    <#elseif categoryName == "managementwetenschappen" /> 
78        <#assign colorKey = " bg--mw " /> 
79    <#elseif categoryName == "onderwijswetenschappen" /> 
80        <#assign colorKey = " bg--ow " /> 
81    <#elseif categoryName == "psychologie" /> 
82        <#assign colorKey = " bg--psy " /> 
83    <#elseif categoryName == "rechtswetenschappen" /> 
84        <#assign colorKey = " bg--rw " /> 
85    <#else> 
86        <#assign areaName = languageUtil.get(locale, 'WETENSCHAPS_GEBIEDEN') /> 
87        <#assign algemenePagina = true /> 
88    </#if> 
89 
90<#-- Contactformulier URL --> 
91    <#assign linkcontactformulierurl = "/web/open-universiteit/" + link_contact_formulier /> 
92    <#if Pagina_Koppeling != ""> 
93        <#assign linkcontactformulierurl = Pagina_Koppeling /> 
94    <#elseif Link_Koppeling != ""> 
95        <#assign linkcontactformulierurl = Link_Koppeling /> 
96    </#if> 
97 
98<script type="text/javascript"> 
99    function printFunction() { 
100        window.print(); 
101
102</script> 
103 
104<!-- START FULL IMAGE --> 
105<section class="container-fluid section padding-top padding-bottom-large" ou-aera="${categoryName}"> 
106    <div class="full-image full-image--home"> 
107        <div class="full-image__bg"> 
108             <div class="full-image__bg__img" style="background: url('${sfeerbeeld_url}') no-repeat center; background-size: cover; z-index:1;"></div> 
109            <div class="gradient" style="z-index:0;"></div> 
110        </div> 
111 
112        <div class="full-image__content"> 
113            <div class="layout__content-container"> 
114                    <div class="row"> 
115                    <div class="col-md-12"> 
116                        <#if !getterUtil.getBoolean(Titel_Verbergen.getData())> 
117                        <div class="full-image__content__title">${.vars['reserved-article-title'].data}</div> 
118                        </#if> 
119                    </div> 
120                </div> 
121            </div> 
122        </div> 
123    </div> 
124</section> 
125<!-- END FULL IMAGE --> 
126 
127<!-- START SECTION - CONTENT INTRO --> 
128<section class="container-fluid section"> 
129    <div class="layout__content-container"> 
130        <div class="content"> 
131            <div class="row"> 
132                <div class="content__left col-xs-12 col-md-8 pull-top"> 
133                    <div class="intro__content ${colorKey}"> 
134                        <h1 class="intro__title"> 
135                            ${Introductie_Titel.getData()} 
136                        </h1> 
137                        <div class="paragraph--intro"> 
138                            ${Inleiding.getData()} 
139                        </div> 
140                        <div class="intro__content__inner"> 
141                            ${Artikel.getData()} 
142                        </div> 
143                        <div class="social-media social-media__intro"> 
144                            <ul class="social-media__container"> 
145                                <li class="social-media__item"><a href="${mailto}" class="fa fa-envelope-o"></a></li> 
146                                <li class="social-media__item"><a onclick="printFunction()" class="fa fa-print"></a></li> 
147                            </ul> 
148                        </div> 
149                    </div> 
150                </div> 
151 
152                <div class="content__right col-xs-12 col-md-4"> 
153                    <div class="intro__right"> 
154                        <#if Persoon_Tonen=="true"> 
155                            <div class="person"> 
156                                <div class="person__container"> 
157                                    <#if Persoon.Persoon_Foto_Url.getData() != ""> 
158                                        <div class="person__photo person__photo__large" style="background: url(${Persoon_Foto_URL}) no-repeat center; background-size: cover;"></div> 
159                                    </#if> 
160                                    <div class="person__name">${Persoon_Titel} ${Persoon_Naam}</div> 
161                                    <#if Persoon_Functie?has_content && Persoon_Functie != ""> 
162                                        <div class="person__function">${Persoon_Functie}</div> 
163                                    </#if> 
164                                </div> 
165                            </div> 
166                        </#if> 
167                        <div class="content__right__actions"> 
168                            <a href="${linkcontactformulierurl}" class="btn btn--center btn--tertiary"><@liferay.language key="VRAAG_STELLEN" /></a> 
169                        </div> 
170                    </div> 
171                </div> 
172            </div> 
173        </div> 
174    </div> 
175</section> 
176<!-- END SECTION - CONTENT INTRO -->