Hello Roman

Sorry for the late response.

These errors can happen for a few reasons, but they always happen for server-side tables (MySQL, manual, or imported tables).

Check if you have any errors, notices, warnings in your console. If there are, resolve them first because they are interrupting wpDataTables' admin-ajax calls and the errors returned are referring to either bad Ajax or bad JSON response.

Another thing that could be causing this is cache. If the data is being cached on the page, the returned data is not the same, or not at least what wpDataTables is expecting to see, so the error occurs. Try clearing all cache from your website and browser, and then prevent the pages containing wpDataTables from being cached.

Last, it could be the data in the table(s) - if the data is not the type that it should be (for example, a non-numerical value in an integer or a float column), or if the data has been changed for a formula column. Try creating a new table from the source table and see if it's going to cause errors. If it doesn't (after excluding cache as the cause), look for differences between data, filters, etc.

I hope that helps.

Hi, Roman

- We can see you created another ticket for this issue; we advised you on it to avoid creating duplicate tickets.

As colleague Aleksandar already covered all possible scenarios as to what might be causing these errors;

I can just try to clarify one detail for you (a part of what Aleksandar already said), this error in the console right here, I will show you on the screenshot, is not caused by our plugin. You have to fix that first and then come back to us if still not resolved.

- Here is a documentation page from datatables.net that explains everything about this error you got in the console (DataTables is the javascript/jQuery based library, which is the foundation that wpDataTables is built on).

- That being said, please go through everything mentioned in the previous reply, and that should help you isolate the issue.

Sorry about that, Roman, I just realised that you responded in the meantime. 

We will close this ticket. Thank you for letting us know it has been resolved.

If anything else happens, of course, don't hesitate to create new tickets.