Template Issue Going from 3.8.7 to 4.2.1

[JamesN]

I've upgraded a test copy of my forums from 3.8.7 to 4.2.1 and am incorporating my Google Ads into the new template structure.

In the postbit_legacy template in 3.8.7, I had the below code. If I add it to the postbit_legacy template in 4.2.1 I get the attached error.

<if condition="$post[postcount] % $vboptions[maxposts] == "4"">
<table class="tborder" cellpadding="6" cellspacing="0" border="0" width="100%" align="center" style="margin-top: 1px; border-top: 0">
<tr valign="top">
<td class="alt1" align="center">
<!-- show google script -->
</td>
</tr>
</table>
</if>

How can I do this in 4.2.1?