Have just tested the original Seedcode Calendar Pro under Filemaker Pro V10 on both Windows and Mac.
Both are giving me same errors when trying to use various buttons.
eg

"the layout name passed as a parameter to this script (Mini Window Create Appointment ? Schedule) is not the name of a layout in this file."

I can see that the layout is still there in the file, its editable and OK.

So far its only the "Mini Window Create Appointment ? Schedule", the "Legend window" but they are across all TABs.

The FM10 backward compatability notes do not mention this topic.

Is anyone else having an issue?

Also "Mini window select Date"

The error is coming from script "New Mini Window"

Solved: I was testing with a file called "TEST V10.0" and this caused the problem. It doesn't like a period in the file ( other than the period before the extension.