Michael,
We are going to need you to be a bit more specific as to how and when you are getting this error message. First, what exactly are you making into a dynamic block? Are you getting this error message when creating this block? Or have you saved the block fine, but you are now trying to save it into the Land F/X block location? Sending in the file may help as well, so please send the errant file using our Ticket system.

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