Unable to convert sender system XXXX to an ALE logical system

Hi Friends,

I am facing the below error in moni, I can see there are so many blogs with this error. just want to understand the process as per my requirement.

error: unable to convert sender system XXXX to an ALE logical system.

sender system---> business system(File)

Receiver system -->Business system(idoc)

1.In this scenario for Idoc receiver system we have maintained logical system in adapter specific identifier, so do we need maintain same for sender file system also to avoid this error??

2.for the sender file system I checked in SLD, there is no logic system maintained. we need to configure in SLD?

3.If BPM involved in this scenario, what could be the reason for this error?

Thanks,

Janardhan