Following to an upgrade of the engine to 12.3.1 following error messages can be found in the java communication process log file:
CP_srv_log_004_00.txt:20200209/090322.386 - 32 U00009907 Memory dump 'Unauthenticated message from 36' (Address='n/a', Length='000003')
CP_srv_log_004_00.txt:20200209/090322.386 - 32 00000000 090144 >..D<
CP_srv_log_004_00.txt:20200209/090322.394 - 32 U00003489 Server 'UC4P#WP005' logged on (Client connection='36').
In the WP logfile following messages can be found for teh same period:
17 - 20200208/213310.484 - U00003389 Server 'UC4P#WP017' has changed its mode from 'WP' to 'DWP'.
16 - 20200208/213316.290 - U00003389 Server 'UC4P#WP016' has changed its mode from 'WP' to 'DWP'.
18 - 20200208/213316.509 - U00003389 Server 'UC4P#WP018' has changed its mode from 'WP' to 'DWP'.
No defect is present in the application.
AUTOMATION ENGINE : 12.3
A behavior has been improved where a timing condition could've lead to the message "Memory dump 'Unauthenticated message from ..." in the log file of a JCP.
This could happen if a WP logged on to CP and changed its mode (for example WP to DWP) at the same time.
This is a bug corrected in 12.3.3 of the Automation Engine. Upgrade to this service pack or to a more recent to have the probem fixed.