Alert: when editing / saving a calculator i get an alert "DataTables warning"

Hello,

Please send us the test website credentials here: altoswebsolutions.com/contact-us

Use as form subject: "AT1550"

And add the following information:

- Test website credentials
- Name/ID of the calculator
- Instructions (Clicks) how to reproduce the problem

Kind Regards,
Enrico
AT1550

DataTables warning: table id=awspricecalculator_select_products_table - Invalid JSON response. For more information about this error, please see datatables.net/tn/

How can i get rid of this.