I cannot view Activities on a Contact's Activities Tab, or my activities on my CiviCRM Dashboard. In both cases I receive the following error:
DataTables warning: table id=DataTables_Table_0 - Invalid JSON response. For more information about this error, please see http://datatables.net/tn/1
I am using CiviCRM 4.7.28 in Wordpress 4.9.1. I have the following Extensions active in CiviCRM:
- iATS Payments 1.6.1
- Summary Fields v. 3.1.1
- Extended Report v. 3.0
- Displays relationships in the contact summary v. 1.2
- Mailchimp v. 2.0.1