Error 1025 error on rename of

[Jose María Tristán Martín]

Hello:

I have a table whith one field "idActividad" that is autonumerique and primary key.
I want change the name of the fiel to "idActividadXCentro", but it send the next error:
ALTER TABLE 'yachar'.'actividadespreventiva' CHANGE COLUMN 'idActividad' 'IdActividadXCentro' INTEGER UNSIGNED NOT NULL DEFAULT 0,
DROP INDEX 'Index_1'
ADD INDEX 'Index_1' USING BTREE('IdActividadXCentro');


MySQL Error Number 1025
Error on rename of '.\yachar\sql-8ac_1' to '.\yachar\actividadespreventiva' (errno: 150)

Thank you very much.