WPF - Compilation error: Tags of type 'PropertyArrayStart' are not supported in template sections
It's been an eventful 27 minutes... :)
Changing the dependency property's type from unit[] to IList<unit> solved the problem. Best of all, it didn't requite many code changes as the array already implements that interface.
I'm not sure whether dispatching to the array via the interface (callvirt) is slower. My guess is yes.
The original error message hints that there's something going on here that I don't quite understand. I'll accept any answer that explains it properly.