Fehler "The server aborted the import without any error message..." bei Shopware Migration beheben

Fehlermeldung:
The server aborted the import without any error message. Usually this is caused by low max-execution limits or SQL-server timeouts.What can you do about this?* Check your max-execution timeout* Check your mysql server configuration* Add additional indizes to your source database in order to speed up the queries. Please refer to our documentation regarding the last option.

Mögliche Ursachen:

max_execution_time zu niedrig eingestellt.
Lösung: max_execution_time höher einstellen, z.B. mit folgendem Befehl in der .htaccess:
php_value max_execution_time 300