PHP Warning "explode() expects parameter 2 to be string, array given" for multi-value country fields
I am getting above error while trying to save multiple country for agent profile. And when I search about this error I found that unnecessary use of explode() function on line 127. You can see more about on #216 (closed) and code file https://lab.civicrm.org/dev/core/blob/master/CRM/Core/BAO/CustomValueTable.php#L127
So according to me you need to ask to civiCRM team to comment line 127 $mulValues = explode(',', $value);