Camm rule save error

[Moegoe]

Hi. I have Camm1.6.75 running on Cacti v1.2.4 on Ubuntu16 new install. I can create a rule but can not save it - i keep on getting this error

camm_rule_error.PNG (5.24 KiB) Viewed 8240 times

This is all the log shows:
2021/02/01 13:03:58 - camm php camm_save_rule ids=[[{"json_filter":"{\"fieldId\":\"message\",\"operatorId\":\"STRING_CONTAINS\",\"values\":[{\"label\":\"enable\",\"value\":\"enable\"}]}","sql_filter":"message like '%enable%' ","sup_mode":"","date":"2021-02-01T13:08:21","id":100}]]