Login phpMyAdmin, find the cscart_products table and delete the parent_product_id column before module installation. Make a backup just in case
Thanks for you Answer but my Problem is no solved. After delete the parent_product_id column have try again to install this Add-Ons and now i have this Error-Message:
An error in an SQL query occurred during the add-on installation. The add-on will not be installed.
INDEX command denied to user 'xxxxxxxxxxx'@'localhost' for table 'cscart_products' (1142): CREATE INDEX idx_parent_product_id ON cscart_products (parent_product_id);
Have Problem solved, see Screenshot
thanks for posting the answer