details below

Critical Error during the update process:

/example.com/piwik/core/Updates/1.2-rc1.php:
Error trying to execute the query 'ALTER TABLE piwik_log_visit
DROP visit_server_date,
DROP INDEX index_idsite_date_config,
DROP INDEX index_idsite_datetime_config,
ADD visit_entry_idaction_name INT UNSIGNED NOT NULL AFTER visit_entry_idaction_url,
ADD visit_exit_idaction_name INT UNSIGNED NOT NULL AFTER visit_exit_idaction_url,
CHANGE visit_exit_idaction_url visit_exit_idaction_url INT UNSIGNED NOT NULL,
CHANGE visit_entry_idaction_url visit_entry_idaction_url INT UNSIGNED NOT NULL,
CHANGE referer_type referer_type TINYINT UNSIGNED NULL DEFAULT NULL,
ADD idvisitor BINARY(8) NOT NULL AFTER idsite,
ADD visitor_count_visits SMALLINT(5) UNSIGNED NOT NULL AFTER visitor_returning,
ADD visitor_days_since_last SMALLINT(5) UNSIGNED NOT NULL,
ADD visitor_days_since_first SMALLINT(5) UNSIGNED NOT NULL,
ADD config_id BINARY(8) NOT NULL AFTER config_md5config,
ADD custom_var_k1 VARCHAR(50) DEFAULT NULL,
ADD custom_var_v1 VARCHAR(50) DEFAULT NULL,
ADD custom_var_k2 VARCHAR(50) DEFAULT NULL,
ADD custom_var_v2 VARCHAR(50) DEFAULT NULL,
ADD custom_var_k3 VARCHAR(50) DEFAULT NULL,
ADD custom_var_v3 VARCHAR(50) DEFAULT NULL,
ADD custom_var_k4 VARCHAR(50) DEFAULT NULL,
ADD custom_var_v4 VARCHAR(50) DEFAULT NULL,
ADD custom_var_k5 VARCHAR(50) DEFAULT NULL,
ADD custom_var_v5 VARCHAR(50) DEFAULT NULL
'.
The error was: SQLSTATE[42000]: Syntax error or access violation: 1091 Can't DROP 'index_idsite_date_config'; check that column/key exists
Keywords: update, piwik 1.2