Why can't I run a tour with this setup?

[Wolffpack]

I'm working on a project that is a tour of 13 sites. I've setup a folder which contains 13 subfolders, one for each site. Each subfolder contains a placemark and one or more overlays. If I try to run a tour from the main folder I get the Tour Failed message stating "There are no placemarks selected for the tour...". Each of the placemarks are selected and I can individually run the tour of any of the 13 subfolders, but not the main folder.

I'm currently on GE 3.0.0762.

What am I doing wrong here?

[GEH4EVR]

May I see the file?

[Wolffpack]

It's too large to upload as an attachment but you can find it at www.packowolffs.com/2sitetest.kmz. This test only has two of the 13 sites to visit.