Labels printing : "unable to read format"

Question

Hello
I have configured a Printronix Label printer as a network printer (Acess Method U).
Communication test is successfull
But when I execute a printout I have the following message:
=========================
Print request processing log
Errors occurred processing this print request
Unable to read format ZDINA6. l_rc = 1
There may be no printout
=========================
Despite format ZDINA6 is properly associated to the Device Type (ZPTXASC4) of the printer.
Inizialization commands are all empty, as suggested by Printronix Manual
What am I missing?
Thank you!

Answer 1

Thanks David and Lokeswara for your answers.
Oss did not help actually: I also tried with Postscript type, instead of STDN II, but did not succeed.
As to ZDINA6 format: it is in use in their old system, same labels, same configuration; a part from the access method, because they currently have a Win NT print server in between that the new system does not contemplate.
Still a mistery, at least to me..
Thank you for now