It is possible that one or more of the files in your download of ZC sfotware have become corrupted.

As you are not making any progress, then my advice is to do the following.

1. Get another copy of the ZC software and remove the old copy from your machine.

2. On your host c-panel, or via phpMyAdmin, DROP every table in the database. Empty it out completely. You may even want to DELETE that database, and create a brand new one.

3. Send all the folders of ZC back to the server, OVERWRITING those that are there. (Or you could delete those currently on the server).

Basically, start from scratch.