I think there are 2 independent issues going on.

1.) the folder structure needs to be renamed properly (with almost all module installations): Avalan should be renamed after your template. and zcadmin should be renamed to the name of your admin.

2.) once those are changed you will also need to run the SQL patch under Tools->Install SQL Patches and select the Install SQL that corresponds to your version of zencart.

Do these solve your issue?