Hi -
Few Check Points -
- Try executing Error idoc using WE19 in foreground mode and check where exactly error is coming.
- Is Number range maintained for supplier in ECC2.(Is it Internal or External)
- All mandatory fields should be mapped with IDOC Structure of your LSMW
- Did you performed a step of activating IDOC inbound processing and maintained File port using WE21.
- Did you maintained Partner type and Partner no using WE20.
You can also transfer suplliers by setting up an ALE between two systems by using message type CREMAS05.
or if you will explain about an error little more then we can help you in better way.
Thanks & Regards
Amit Gupta