I was required to install the Module Manager add-on for Zen Cart because it is required by the Simple SEO URL Zen Cart add-on requested by a client of mine. During the install process you visit the Module Manager section in the Zen Cart admin and I received an error complaining that a specific file did not exist. Below is a quick description of the error and what was done to resolve it.
Zen Cart Module Manager Add On: Failed To Create .keep File
As you can see above when visiting /admin/module_manager.php an error appears above the page that is displayed and states that it had trouble creating the .keep file. This error probably related to some form of permissions where the installation script didn’t have the proper permissions to create a new file in the /admin/includes/module_installation directory. To resolve the error you simply need to create a .keep file in this directory so the entire path to the .keep file will be /admin/includes/module_installation/.keep. If you have SSH access to the server you can touch .keep in that directory or if you only have FTP access to that directory then you can create a .keep file locally and upload it to the proper directory on the server.
Zen Cart Module Manager Add On: .keep File Errors Resolved
You should now be able to visit the Module Manager admin section in Zen Cart without receiving any further errors.