Steps to reproduce:

1. Insert > Template
2. Click the "Show options" button at the bottom.
3. Click the "[ ]" button at the bottom (the tooltip says "Add content").
4. Paste wikitext in there.
5. Realize that the "Insert" button is still incorrectly grayed out. There's no way to insert or save this.

Expectation:

When you add stuff to a dialog, the "Insert" button should wake up.

Workaround:

1. Click the red trashcan icon to delete the empty "Template" blank above the content.
2. Click the now-green "Insert" button.