.....
> I red in the Error Messages Manual that the subsystem 102 was the
> Process Manager but there were no error message '1457'. I performed
> the soft reset and the system has gone up without troubles.
> Everything is O.K. now (I hope) but I'd like to know what happend
> and why. And what to do if it happens next time.  :)
>
> I don't know where to look for an explanation of the above.
> I'll be very grateful if someone tells me the that.

system abort is subsys 98; execute

xeq msgutil.pub.sys '98,1457'

and you will get
SYSTEM ABORT
-------------------------------------------------------------------------
A system process is being terminated due to a trap.
SYSTEM ABORT message 1457
-------------------------------------------------------------------------

to find the reason for this sa it is necessary
to investigate the memory dump taken after the sa.