Stock by Attribute v1.4.13 install issue

[d2md]

Hi - first time posting, appreciate any assistance.
Zencart 1.3.9g
Stock by Attribute plug in 1.4.13

All files will install ok, sql patch uploads fine. New products by attributes appears in dropdown and page loads. However, once we logout of the admin control panel in ZCart, I cannot log back in. The admin info goes away and the website does not load again. Dead. Resend password goes nowhere. I restored back up, stepped through multiple items and have determined that all admin/user data is removed when the new admin files are uploaded. If you remain logged in during the process, you can see the product listing in the drop down, you can go to the admin panel and try to add a new user or admin, but it does not compete the entry. The install has been running over a year and this is the first add on we are trying. admin file was renamed to match our admin folder name prior to upload. Files all show up in file listing. I want to love this add on, it seems to do exactly what I need it to, if I can get it to function. Thanks in advance! - D

[d2md]

More Info/Update:
Folder contains update_1_4_10.sql, but no details in the installation instructions. Does it get imported too?