Importing a staged record batch is returning the Koha web installer option. To recreate: 1) Go to Tools --> Manage Staged Records. 2) Choose a batch. 3) Click on Import this batch into the catalog. 4) Note the Welcome to the Koha web installer message that appears.
This is due to a problem with the DB handler. It is fixed by bug 14778. *** This bug has been marked as a duplicate of bug 14778 ***