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Open upgrade.sql file in text editor and replace beginning of table names (prefix) "ac_" with your tables prefix selected at original installation. Easiest way to replace all "ac_" instances with your table prefix via your text editor's Find&Replace tool. To check prefix, you can open your database and check beginning of all AbanteCart tables. If you did not use prefix, replace with empty.
Run modified upgrade.sql
Run modified upgrade.sql file in MySQL (command line, phpMyAdmin or other )
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