Avatars For Multisite - Upgrade Issue

This is what I'm getting when trying to upgrade this plugin:

The update process is starting. This process may take a while on some hosts, so please be patient.

Enabling Maintenance mode…

Updating Plugin Avatars For Multisite (1/1)
An error occurred while updating Avatars For Multisite: Update package not available..

Disabling Maintenance mode…

All updates have been completed.