Hi,
Probability of receiving Failure 1(GENERIC_OPERATION) when using TSAPI protocol for makecall.A CSTA_MONITOR_ENDED will be received shortly,then CTI application have to remonitor the device.
The AES is Avaya Aura AES SW Version: 6.3.3.11.10-0 SuperPatch 11 and LSUP 5 and Avaya Aura Communication Manager R016x.03.0.124.0 Patch 13

As I understand your question when attempting to do a MakeCall() operation from a TSAPI application,
you receive back a GENERIC_OPERATION error (1)
Shortly thereafter the application receives a monitor ended event
and must re-establish the station monitor.

My guess is that the link between AES and CM failed, and was noticed at the point in time when the MakeCall() was requested. The failure of the link, caused AES to terminate the station monitors that were active using that link.

Examine the AES /opt/mvap/mvap.log file for insights as to what was happening with the link at the point in time that the MakeCall was sent. By now it may be in one of the roll over logs ... mvap.log.[0-9]

Sorry, I didn't find mvap.log in /opt/mvap/ folder

Look in /opt/mvap/logs. There should be several mvap log files in there.

Is it necessary to adjust the log level first?

The AES SW Version: 6.3.3.11.10-0
ERROR log should be log (log.yyyymmdd, for example log.20050622) ?

TSAPI Service
All logs, except the trace log and the G3trace log, are in /var/log/avaya/aes, as follows:
• Security (client) log (sec.yyyymmdd, for example sec.20050622)
• Error log (log.yyyymmdd, for example log.20050622)
• Command log (cmd.yyyymmdd, for example cmd.20050622)
• Reset log (reset.log)
• Trace log (/var/log/avaya/aes/common/trace.out)
• G3trace logs are located in /var/log/avaya/aes/TSAPI. This directory includes g3traceswitchname-n.trace.out, csta_trace.n.out, and audit_trace (where switchname is the name of
your switch and n is a number).
• Import SDB log (importsdb.log)

Sorry I looked at an R8 system to remember what the log file was named.
• Error log (log.yyyymmdd, for example log.20050622) is what you want to review.