> %SDA-F-OPENIN, error opening SYS$COMMON:[SYSEXE]SYSDUMP.DMP; as input
> -RMS-E-FNF, file not found

> SEEMS LIKE THE UTILITY IS OFF OR SOMETHING [...]

   Seems like the system manager is off or something.  You might want to
read the system management docs for a while to learn more about the
crash dump file (and its friends).

> how can i restart the syste error log utility, so that when it happens
> again i can capture the error

   I'd start by solving the problems that you have found (like, say, no
crash dump file), and then go looking for more trouble when you have a
better idea of what to look for.  Error logging has little or nothing to
do with a missing crash dump file.

   If the documentation is not interesting enough, then you might try
something like, say:

      @ SYS$UPDATE:SWAPFILES.COM

Or investigate:

      SYS$UPDATE:AUTOGEN.COM

Possibly, as a start:

      @ SYS$UPDATE:AUTOGEN.COM GETDATA TESTFILES