civi 5.9.13 WP 5.2.2 civi In a contract screen activities tab no activities are listed error popup says "DataTables warning: table id=DataTables_Table_0 - Invalid JSON response. For more information about this error, please see http://datatables.net/tn/1" EEK! I've recently deleted various mysql data related to civivolunteer - hope this didnt break anything

PS I tried the fix here: DataTables Warning: Cannot view Activities after upgrade to 4.7.28 didn't work

1 Answer 1


Answering my own question. On checking logs it was in fact missing civivolunteer custom fields. restored them from backup and all good now.

Is this bad behaviour for an extension?

  • How did you delete the data? Your reference to deleting 'mysql data' suggests you might have done this with direct sql - in which case the extension doesn't get chance to clean up any dependencies resulting in an inconsistent state. On the other hand if you deleted via GUI and/or API then it should cope but if not, log an issue.
    – Aidan
    Apr 6, 2020 at 15:34

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