foreing key which accept null

I think it is a bug, the later week I have found several error with complex queries that not work in Scriptcase,but it does on mysql Workbench
The problem is your create an foreig key which accept null.
I yoy try to insert a register with this field equal null, you get an erro
Cannot add or update a child row: a foreign key constraint fails

But this query is executed on mysql -workbench, the is not problems

INSERT INTO T101Cliente (cliente, tipoContacto109, empresa101, Cargo, provincia10, email, web) VALUES (‘cliente MOAR’, 1, 0, ‘’, 21, ‘’, ‘’).

Regards

THe problem was reported some years ago. This a Bug with SC. IF the value is NULL then SC changes the Value of NULL to ZERO.
A solution is create a record with Value ZERO in the other table.