Fixed it - Display "Defaults" has an invalid style plugin.

Ok this Drupal 7 conversion is getting a little trying but I think I'm almost ready to buy a ticket to DrupalCon. I couldn't get the 'view' for the new 7.3 calendar to work because of the error that went along with the following:

Display "Defaults" has an invalid style plugin.

Unable to preview due to validation errors.

I was completely lost, I gave up grabbed a turkey sandwich and had an idea. Messing with drupal is like messing with the bread, I needed to poke at the turkey - MySQL. The I fixed it and posted the quick fix to Drupal.org because we all need more time for turkey this fall. Here is that post:

Woo- Fixed it manually.

Ok here it is:
1) Disable the Calendar and iCal Modules
2) Go into you DB for under ctools_object_cache you will find your broken calendar despite the disable
3) Drop it, delete it, kill it with fire (leave your other views that work.
4) Re-enable the Calendar module and it will regenerate a clean version of the new calendar system

Until the next Calendar release that should fix your problems, if you're willing to dive into it. 100% success rate.