TYPO3 Exception 40

Note

Below, the TYPO3 community may have provided additional information or solutions for this exception. However, these may or may not apply to your particular case. If you can provide more information, you should come back here and add your experience and solution steps to this issue once you have resolved it.

General TYPO3 troubleshooting tips can be found in the Troubleshooting section in the menu. You can also ask questions and receive support in the TYPO3 Questions category on talk.typo3.org.

To add your experience, click "Edit on GitHub" above and follow the "Edit on GitHub" workflow. Also check out our tip on Coding Style and reST.

Indicates an SQL error has occurred, please check your ext_tables.sql files.

For example:

The column 'columnname' on table 'tablename' already exists

This happens for example if the file ext_tables.sql of a TYPO3 extension has the same field twice for a table.:

CREATE TABLE sys_products_fe_users_mm_visited_products (
    uid int(11) NOT NULL auto_increment,
    pid int(11) DEFAULT '0' NOT NULL,
    tstamp int(11) DEFAULT '0' NOT NULL,
    crdate int(11) DEFAULT '0' NOT NULL,
    deleted tinyint(4) DEFAULT '0' NOT NULL,
    hidden tinyint(4) DEFAULT '0' NOT NULL,
    tstamp int(11) unsigned DEFAULT '0' NOT NULL,
    uid_local int(11) DEFAULT '0' NOT NULL,
    uid_foreign int(11) DEFAULT '0' NOT NULL,
    qty int(11) unsigned DEFAULT '0' NOT NULL,

    PRIMARY KEY (uid),
    KEY uid_local (uid_local),
    KEY uid_foreign (uid_foreign),
);

There are 2 fields tstamp in the table sys_products_fe_users_mm_visited_products

Removing the second line with the field tstamp from table sys_products_fe_users_mm_visited_products fixes the problem in this case.