php notice in user/register/XXXX

When anonymous user access to user/register/CICE?lang=es it reports:
Notice: Undefined index: default_lang a ces_bank_form_alter() (line 1191 ices/ces_bank/ces_bank.module).

When anonymous user access to user/register/EXBA?lang=es it reports:
Notice: Undefined index: default_lang a ces_bank_form_alter() (line 1191 ices/ces_bank/ces_bank.module).