What is this error (Error number: -29)?

[daitranthanhoa]

I using Indesign Server CS6 and  call script from cmd:

sometimes it return error: Error from InDesign server. Error number: -29

What is this error?

to duplicate error is very difficult.

20/1 occur this error on port 201

18/5 occur this error on port 203

event log:

Because we are using Indesign CS 8.1 to edit file indesign and upload to indesign Server ver 8.0.2 to export to pdf.

Is it the cause?

Must we upgrade indesign server version ? Exist Indesign Server version 8.1?