Hi cfcpac,
Thank you for your purchase.

Can you please tell me did you follow this steps when updating the plugin

1.) Download zip from this link

2.) Use FTP to open /yourwordpressfolder/wp-content/plugins

3.) Delete existing wpdatatables folder.

4.) Upload previously downloaded wpdatatables folder through FTP to plugins folder (unzip it)

5.)  Go to WP-admin panel, open Plugins section.

6.) Deactivate wpDataTables, and then activate it again.

Also I suggest you to clear the browser cache and deactivate/activate the plugin again.
Let me know the result.