The following has evaluated to null or missing:
==> category_list  [in template "sub-top.ftl" at line 9, column 19]

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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: @category_list websiteId="#{website.i...  [in template "sub-top.ftl" at line 9, column 17]
	- Reached through: #include "sub-top.ftl"  [in template "文章详情.ftl" at line 38, column 3]
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