Error received when trying to add a condition in the Trigger Wizard

I was trying to add a condition to a trigger I had. I want the next button to be disabled until 3 layers are viewed, and then it returns to normal once all buttons are Visited. However, when I return to the slide after going forward in the course, the next button returns to disabled because of the first trigger "when timeline starts, change state of next button to disabled." I found some options to fix this in the forum, but I keep getting an error. I clicked on +if in the Conditions box of the Trigger Wizard and then selected Objects, and I immediately get an error report window. 

Is this a known error? Is there another way to add conditions to a trigger?