This is a repeatable [but not fatal] bug in V1.3.5:
When using Zen Cart Installer
Step - Database Setup
Form - Database Information
Field - Store Identifier (Table-Prefix)
The Store Identifier field does not show up initially on the Database Information form. Therefore, you cannot specify a db prefix (i.e. zen_).
Workaround:
Leave the form blank and click "Save Database Settings".
This will force an error return page and the Store Identifier field will now show up and function as expected.
Regards,



