[Aaron]

Well, if I understand what you're saying, the "add a template" text is red, but the validation warning isn't appearing, and for some reason that's a problem for you. Here is the XML for the relevant validation error:

    <evalrule
      index="2"
      phase="Validation"
      priority="10000"
      message="You must apply a template to this summoned monster!"
      summary="Summoned Monster template required!"><![CDATA[
      ~the rest only applies if we're NOT the race of a fused Eidolon - the
      ~real race is the one in the hero container, and it applies these effects
      validif (container.ishero = 0)

      ~ This is not important if the hero is not a summoned creature
      validif (hero.tagis[Hero.Summoned] = 0)

      ~ We only need to check this if we are a race which sometimes requires
      ~ a summon template, all others are automatically valid.
      validif (tagis[Hero.NeedSumTem] = 0)

      ~ Even if we are a summoned creature and could require a template, we won't
      ~ actually require one unless the user checks the "Template Required?"
      ~ checkbox to indicate for this spell the template is needed.
      validif (herofield[tSumTempRq].value = 0)

      ~ Finally, if all the other tests are passed, then we need to check that
      ~ a valid template has been added to the hero, as indicated by a hero tag.
      validif (hero.tagis[Hero.HasSumTem] <> 0)
      ]]></evalrule>

Your adjustment isn't in a container, it is on the hero so the first validif shouldn't be satisfied.

You said you checked the Summoned Creature source in the config, and I believe that applies the Hero.Summoned tag. So that shouldn't trip the 2nd validif

Your adjustment is applying Hero.NeedSumTem, so that should be fine for the 3rd.

I'm guessing the fourth, which checks that herofield, is probably where you're going wrong. Did you check the box for the hero?