How to run "Run a Demo"

Hi all,
I run the example in webmethods EDI homepage according to the introduction.
But It can not run.
The error message is as below:
" [ESIPRT.000000.000029] "
"In service Received document that does not match with any conversation or conversation scripts. ConversationID 58ccbf0v191q50qg0000001k-58ccbf0v191q50ud0000001n-000016 [ESIPRT.000070.000020] "

In the monitor, the step “send to seller” in "EDI_buyer_850_855 Model " run successfully. But the step “Wait to Order” in “EDI_Seller_850_855 Model” can not run, Why??
See the attachment. Who can help me? Tks!