IDoc receiver channel: connection factory name for channel is null

Hi,

This is related to Production Support. ECC system was planned to maintenance shutdown.

Before ECC is down, I have stopped all PI communication channels (first all sender channels and then all receiver channels) using mass stop from PI MON.

After ECC was back up again, I have started the PI channels in reverse order (receiver channels first and then sender channels). All the channels were up and running fine except IDoc receiver channel. It was showing below error:

IDoc: connection factory name for channel IDOC_RCV_ECC is null

Start and stop of the channels was not not helpful.Then PI system was restarted, post which IDoc receiver channel was up and running fine.

Does anyone have any idea on root cause of this issue? What can be done to resolve this without system restart.

Thanks,

Vertika