The JSON API error 80EA29CA-4525-3AAB-970A-A3D3E22AA10F means "The provided reference date is invalid."
This error occurs when the value of the "reference date" was not provided in a YYYY-MM-DD syntax.
To translate an error code into an easier to read message, use the following code:
%hashItems = ( primary => 'template', action => 'returnmessage', id => $response{'result'}{'UserCode'}, ); my $URI = "https://$Host/json.cgi?apikey=$APIKey&".buildURL(\%hashItems);