Oracle Forms

Terminated with error: <br>REP-713: Invalid printer name "" specified by parameter DESNAME.
We are getting this error when trying to print a report directly from oracle forms 10g
We have recently upgraded from 6i.

Another change being we have migrated from citrix server to unix application server now.
Please help
Below is the code we are using

---Called on click of button
PROCEDURE REPORT_PROC IS
pl_id paramlist;

BEGIN
pl_id := get_parameter_list('TEMPDATA');

IF not id_null(pl_id) THEN
destroy_parameter_list(pl_id);
END IF;

pl_id := create_parameter_list('TEMPDATA');

ADD_PARAMETER(PL_ID,'P_UNIQUE_NUM',TEXT_PARAMETER,NAME_IN('PARA_UNIQUE_NUM'));
ADD_PARAMETER(PL_ID,'ARRAYSIZE',TEXT_PARAMETER,'45');
ADD_PARAMETER(PL_ID,'RUNDEBUG',TEXT_PARAMETER,'NO');
ADD_PARAMETER(PL_ID,'P_DESTINATION',TEXT_PARAMETER,:ctl_rpt.fax_number);
ADD_PARAMETER(PL_ID,'PARAMFORM',TEXT_PARAMETER,'NO');
ADD_PARAMETER(PL_ID,'BACKGROUND',TEXT_PARAMETER,'YES');

run_report_proc('report0001',pl_id);

END;
--called internally within the code
PROCEDURE RUN_REPORT_PROC(P_report_name IN VARCHAR2, P_PL_ID IN PARAMLIST) IS
repid REPORT_OBJECT;
jobidfull VARCHAR2(100);
jobidpart VARCHAR2(100);
repserver VARCHAR2(100);
rep_status VARCHAR2(20) DEFAULT '#';



protocol VARCHAR2(10);
hostname VARCHAR2(50);
domain VARCHAR2(50);
port VARCHAR2(10);
virtual_dir VARCHAR2(200);

BEGIN
repid := FIND_REPORT_OBJECT('rp2rro');
GET_REPSERVER_SETTINGS(protocol,hostname,domain,port,repserver);

SET_REPORT_OBJECT_PROPERTY(repid, REPORT_EXECUTION_MODE, BATCH);
SET_REPORT_OBJECT_PROPERTY(repid, REPORT_COMM_MODE, SYNCHRONOUS);
SET_REPORT_OBJECT_PROPERTY(repid, REPORT_DESFORMAT, 'PDF');
SET_REPORT_OBJECT_PROPERTY(repid, REPORT_DESTYPE, PRINTER);
SET_REPORT_OBJECT_PROPERTY(repid, REPORT_SERVER, repserver);
SET_REPORT_OBJECT_PROPERTY(repid, REPORT_FILENAME, P_report_name);

jobidfull := RUN_REPORT_OBJECT(repid, p_pl_id);
jobidPart := substr(jobidFull,length(repserver)+2,length(jobidFull));
virtual_dir := protocol || hostname || '.' || domain ||':'|| port;
web.show_document(virtual_dir||'/reports/rwservlet/getjobid'||jobidPart||'?server='||repserver,'_blank');

END;