log4Net logging improper message

I've deployed log4Net on 2 different servers. on 1st its showing proper message like:

[ERROR] [2018-01-25 19:17:00,856] [MANSOUR3185] [GicCipDataObjects.Oracle] [GetAllRequest] - DB Error System.Data.OracleClient.OracleException (0x80131938): ORA-01722: invalid number

but on 2nd server it is not logging proper message:

[ERROR] [2018-01-25 19:17:00,856] [MANSOUR3185] [GicCipDataObjects.Oracle] [GetAllRequest] - DB Error System.Data.OracleClient.OracleException (0x80131938): ORA-01722: ÑÞã ÛíÑ ÕÇáÍ

I've highlighted both. configuration is same on both servers. Need help.