Error when rebuilding after adding related entries template module

Here's that error again for those that don't want to vide the source code:

An error occurred publishing entry 'Do I Need To Go Pro?': 
Publish error in template 'Entry': Error in <mtInclude> tag: 
error in module Related: Publish error in template 'Related': 
Error in <mtentryiftagged> tag: Error in <mtsetvarblock> tag: 
Error in <mtentries> tag: You have an error in your 'tag' 
attribute: Movable Type OR Upgrade

Can you post the code for the related template.

Hi Rob,
I used this code from http://wiki.movabletype.org/Related_Entries

<mt:entryiftagged>
   <mt:setvarblock name="curentry"><mt:entryid /></mt:setvarblock>
   <mt:setvarblock name="relatedtags">
      <mt:entrytags glue=" OR "><mt:tagname /></mt:entrytags>
   </mt:setvarblock>
   <mt:setvarblock name="listitems">
      <mt:entries tags="$relatedtags" unique="1">
         <mt:setvarblock name="listentry">
            <mt:entryid />
         </mt:setvarblock>
         <mt:unless name="listentry" eq="$curentry">
            <li><a href="<mt:entrypermalink />"><mt:entrytitle /></a></li>
         </mt:unless>
      </mt:entries>
   </mt:setvarblock>
   <mt:if name="listitems">
      <h3>Related Blog Entries</h3>
      <ul>
         <mt:var name="listitems">
      </ul>
   </mt:if>
</mt:entryiftagged>

I thought from the error that the problem had something to do with my tags.

Glad you added the Preview button.

Hi Toni. Have you determined whether it's related to the tags on a single entry or a problem with the snippet of code itself? If you save/republish an entry with no tags or with one tag do you get the same error?

I published an entry with two one-word tags and got the following error:

An error occurred publishing entry 'Post Office Plugin': 
Publish error in template 'Entry': Error in <mtInclude> tag: 
error in module Related: Publish error in template 'Related': 
Error in <mtentryiftagged> tag: Error in <mtsetvarblock> tag: 
Error in <mtentries> tag: You have an error in your 'tag' attribute: 
Email OR Plugins

Then I tried publishing an entry with no tags and got the following error:

An error occurred publishing entry 'Add a Menu Bar to 
MT's Default Themes': Publish error in template 'Entry': 
Error in <mtInclude> tag: error in module Related: 
Publish error in template 'Related': Error in 
<mtentryiftagged> tag: Error in <mtsetvarblock> tag: 
Error in <mtentries> tag: You have an error in your 'tag' 
attribute: CSS OR Menu Bar OR Navigation

I can't publish the entry template without errors either.

Notice the second error, with no tags? I was still working on the same entry "Post Office Plugin". MT has quoted the previous entry in my list which I was not publishing. Maybe this is a javascript error?

Thanks for your help guys, but I've fixed this problem.

I remember reading on the Devlounge post that there must be no spaces in the setvarblock.

eg. I changed the code from this:

   <mt:setvarblock name="relatedtags">
      <mt:entrytags glue=" OR "><mt:tagname /></mt:entrytags>
   </mt:setvarblock>

to this:

   <mt:setvarblock name="relatedtags"><mt:entrytags glue=" OR "><mt:tagname/></mt:entrytags></mt:setvarblock>

and now it works perfectly. 

Thanks for sharing the answer Toni, I googled it and found it.