Could not start communication channel due to an internal error

Hi,

I used SAP SFTP adapter in my receiver Communication Channel. but when I trying to manually start the receiver CC, I got message as

But when I go SXI_MONI check the messages and it says the message is processed successfully. I can't verify if the third party received the file yet, have to wait till Monday.

I am just wondering what is the problem?

Thanks for your input!

Blue