Creating new data element in edifact editor -> error

Hi Everybody

In the EDIFACT editor I created a new control key and I want to build a complete new message. (based on EDIFACT data elements, composites etc).

Now I have to add a new data element. The data element number is 4751. When I want to save this entry I get the following error message:

"Enter a valid value for Identifier, less than 1000."

This message doesn't seem very logical to me.

Any suggestions how to continue?

Regards

Ron