Hi Elvin

Thank you for reaching out to us.

There are only two possible reasons for this that we have encountered so far; wpDataTables was not updated prior to trying to update the addon, and the purchase code was saved with a space (even if it is at the end of the code, so please try adding the code once again just to be 1000% sure there is nothing in there that shouldn't be).

Please confirm both of those reasons don't apply to your case and provide us a temporary WP-admin (administrator) user for your site where this happens, so we could log in and take a look ‘from the inside’ as that’s the most efficient way to see and resolve the issue. 

We do not interfere with any data or anything else except for the plugin (in case that’s a production version of the site), and of course, we do not provide login data to third parties. 

You can write credentials here just check PRIVATE Reply so nobody can see them except us.

Hello Elvin.

Blazenka is out of the office today, so I'll help you out.

I was able to update the add-on without any issues from Dashboard/Updates:

The update process depends on your website's settings, so if it doesn't work from the Plugins section, always try updating it from Dashboard/Updates. Those are done in maintenance mode, so there's little chance that i will break.