Hawking Technology PS12U - Manual (Page 52)

Try disabling bi-directional printing. This can be achieved through
the print server’s setup function. Bi-directional capable printers may
cause a conflict with the PS12U.
Question C
The upgrading process indication bar stops and does not seem to
proceed again while upgrading the print server.
Possible Explanation
There might be a network problem. This causes the upgrading
procedure to fail.
Solutions
1. Check the network cabling, especially from the workstation
running the PSAdmin to the print server unit.
2. Run the PSAdmin and upgrade the print server again.