An error occurred while processing the template.
The following has evaluated to null or missing:
==> .vars['reserved-article-display-date']  [in template "10108#260730#10782806" at line 9, column 24]

Tip: It's the final [] step that caused this error, not those before it.
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: (!myDefault, (

FTL stack trace ("~" means nesting-related):
	- Failed at: #assign displayDate = .vars["reserved...  [in template "10108#260730#10782806" at line 9, column 1]
2Web content templates are used to lay out the fields defined in a web 
3content structure. 
5Please use the left panel to quickly add commonly used variables. 
6Autocomplete is also available and can be invoked by typing "${". 
9<#assign displayDate = .vars['reserved-article-display-date'].data/> 
10<#assign displayDate = displayDate?datetime("EEE, d MMM yyyy HH:mm:ss Z")/> 
11<#assign dateTimeFormat = "dd.MM.yy"> 
12<#assign title = .vars['reserved-article-title'].data> 
14<div class="news-content"> 
15    <div class="news-content-title"> 
16        <h1>${title}</h1> 
17    </div> 
18    <div class="news-content-date"> 
19        <p>${displayDate?string(dateTimeFormat)}</p> 
20    </div> 
21    <div class="body"> 
22        ${Body.getData()} 
23    </div>