If it is not already, you will need to enable and load the IP transport
on the OpenVMS host, and you will want to examine the contents of the X
server log file: SYS$MANAGER:DECW$SERVER_0_ERROR.LOG. You'll also want
to test the basic connection with ping.
[With UCX, one enables the TCP/IP transport by defining the logical name
DECW$INSTALL_TCPIP to be TRUE during the system startup.]
Also try to RUN DECW$EXAMPLES:ICO, the error message is likely to be
more helpful.