I have an SAP BI Portal system and an SAP BW system. In the Visual Administrator of the BI Portal, section 'JCo RFC Provider' I have created some RFC listeners. In the SAP BW system (in transaction SM59), I have created, tested and activated the relevant RFC connections. When I start a JCo RFC Provider in the BI Portal the BW system that it communicates with produces these errors (displayed from SAP transaction SM21): Operating system call recv failed (error no. 104 ) Module nam Line Error text Caller.... Reason/cal nixxi.cp 5087 recv104 NiIRead recv Documentation for system log message Q0 I : The specified operating system call was returned with an error. For communication calls (receive, send, etc) often the cause of errors are network problems. It could also be a configuration problem at operating system level. (file cannot be opened, no space in the file system etc.). Additional specifications for error number 104 Name for errno number E_UNKNOWN_NO The meaning of the value stored in 'errno' is platform-dependent. The value which occurred here is unknown to the SysLog system. Either there is an incorrect error number in the SysLog message, or the tables TSLE2 or TSLE3 are not completely maintained. Technical details File Offset RecFm System log type Grp N variable message data 6 410220 m Error (Function,Module,Row) Q0 I recv104 NiIReadrecv nixxi.cp5087 There is plenty of space left in the file system, the servers can ping each other and there is no firewall between the servers. The tables (TSLE2 or TSLE3) mentioned in the error message do not provide any additional information. Please can you tell me if this error message refers to something specific, or if it is generic: recv104 NiIReadrecv nixxi.cp5087