ORA-12703: this character set conversion is not supported

Hi ,

we backup our database version 11.2.0.1  via RMAN nad Data Protector ,version 6.11 .

After we restart server, backup does not work

RMAN-00571: =========================================================== RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS =============== RMAN-00571: =========================================================== RMAN-03009: failure of allocate command on dev_0 channel at 04/15/2011 12:40:59 ORA-12703: this character set conversion is not supported Recovery Manager complete. [Major] From: ob2rman@orel.cnb.cz "cruv" Time: 04/15/11 12:40:59 External utility reported error. RMAN PID=7287 [Major] From: ob2rman@orel.cnb.cz "cruv" Time: 04/15/11 12:40:59 The database reported error while performing requested operation. RMAN-00571: =========================================================== RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS =============== RMAN-00571: =========================================================== RMAN-03009: failure of allocate command on dev_0 channel at 04/15/2011 12:40:59 ORA-12703: this character set conversion is not supported Developers complaint that apex does not work. Not Found The requested URL /apexcruv/f was not found on this server).