"ACcent execution aborted in module ..."

There are several reasons for failures reported as "ACcent execution aborted in module".
Some are described and detailed in IBM Tech notes (like the DCM related here), others are said to be caused by the inconsistency in the server and client versions.

What I found yesterday was the location of the local copy of the database files that can be passed to the ccm start command with the "-u" flag.

At first we had these lines reported as a warning upon session start. They say in this situation session would start and we saw some operations performed, but some would fail, so it is not safe to ignore these:

ACcent execution aborted in module attr:10028, file /tmp/acAAEFBD.TMP.ac, line 14
ACcent execution aborted in module modinit, file src/base/model_init.ac, line 63
ACcent execution aborted in module remote_client, file src/base/remote_client.ac, line 59
ACcent execution aborted in module remote_client, file src/base/remote_client.ac, line 42
ACcent execution aborted in module base, file src/base/base.ac, line 401
ACcent execution aborted in module base, file src/base/base.ac, line 275
Warning: operand of generic cast has an incompatible type
Starting in multiple server mode.
Set the environment variable CCM_ADDR to machine:PID:IP to send commands to this server.

Then we zerroed out all the user ini files (.ccm.ini, ccm.properties etc.) and started afresh.
Now even the status command failed:

> ccm status
Warning: ACcent execution aborted in 'lscmds:status'
ACcent execution aborted in module lscmds, file src/foci/lscmds.ac, line 136
ACcent execution aborted in module base, file src/base/base.ac, line 401
ACcent execution aborted in module base, file src/base/base.ac, line 325
Warning: Lost connection to engine, exiting
Warning: Command execution failed.
Check user interface log file for error messages.

This helped at the end:

ccm start -d -h -m -nogui -u /tmp/whateverlocation -rc