This is my code:

<#if record.item?has_content>
   <table class="itemtable" style="width: 100%; margin-top: 10px;"><!-- start items --><#list record.item as item>
      <#if item_index==0>
         <thead>
            <tr>
               <th align="left" colspan="6">${item.quantity@label}</th>
               <th colspan="30">Item<br />${item.description@label}</th>   
            </tr>
         </thead>
      </#if>
      <#if item.custcol_misv_do_not_print != true>
         <tr>
            <td align="left" colspan="6">${item.quantity}</td>
            <td colspan="30"><span class="itemname">${item.item}</span><br />${item.description}</td>
         </tr>
      </#if>
   </#list><!-- end items --></table>
</#if>
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This is the error:

 Can't compare values of these types. Allowed comparisons are between two numbers, two strings, two dates, or two booleans.
Left hand operand is a hash+string (wrapper: com.netledger.templates.model.StringModel).
Right hand operand is a boolean (wrapper: f.t.TrueTemplateBooleanModel).
The blamed expression:
==> item.custcol_misv_do_not_print != true [in template "template" at line 200, column 16]

----
FTL stack trace ("~" means nesting-related):
- Failed at: #if item.custcol_misv_do_not_print !=... [in template "template" at line 200, column 11]
----
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custcol_misv_do_not_print is a custom transaction line field of type check box.  It has, until this week, been working just fine.
Upon making a change elsewhere in the code, suddently this template will not even pass Preview without this error happening. 
I have removed the code changes that were made but it still gets the error.