Simple path to error 318...

[Digitall]

1. Create drawing.
2. Create User-Defined cell in Page-1. Set it 123, for example.
3. Create User-Defined cell in Document. Set it
=Pages[Page-1]!ThePage!User.Row_1
4. Create any shape in page.
5. Create User-Defined cell in this Shape. Set it =ThePage!User.Row_1
6. Try to copy this shape to Clipboard. All is OK.
7. Try to move to Document Stencil. And move from DS.

Now try to copy. Error 318.

Now set in User-Defined cell of Document not a link, but value, 123, for
example.

Now try to copy Shape. All is OK.

Value[Page]--->Link[Doc]--->Link[Master]--->Link[Shape]--->Error 318.

Value[Page]--->Link[Doc]--->Link[Shape]---> All is OK.
Value[Doc]--->Link[Master]--->Link[Shape]---> All is OK.
Value[Shape]--->Link[Doc]--->Link[Master]--->Link[Shape]---> All is OK.