Pb with table creation (1005/150) and lost constraint (no replies)

Hi,

I change de definition of a table in workbench got creation pb. I dropped the table a now i can't recreate it. It says that there a pb with a constraint, but it had not been deleted with the table :

The table named `group` with 2 column, I got this message

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LATEST FOREIGN KEY ERROR
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101222 11:14:39 Error in foreign key constraint of table Pharma/group:
there is no index in the table which would contain
the columns as the first columns, or the data types in the
table do not match to the ones in the referenced table
or one of the ON ... SET NULL columns is declared NOT NULL. Constraint:
,
CONSTRAINT fk_group_pharma1 FOREIGN KEY (pharma_id) REFERENCES pharma (id) ON DELETE NO ACTION ON UPDATE NO ACTION