Assign category through a plugin
Okay, I think I figured it out. 1st, I added the getContent()

I changed

    $entry-&gt;showName[] = 22;


to 

    $entry-&gt;getContent()-&gt;showName = 22;


I think the problem is that the category we had set up only allowed for a single value and I was responding with an array.

Someone please correct me if am wrong.