Cross-sheet reference limitation


Hello there,

I have a question about "cross-sheet reference" limitation. I receive the attached error message.

I know there are limitation of number of references, however I could no find a rational for this error. I already created a sheet using a lot of references. Today I am trying to add another reference, but I receive this error message. When I delete some other references to open some space for the references, system does not let me add the new one, Even if delete a large number of references (here; 500 references), I can not add 1 new reference.

Does any one know the reason?