The -1073741819 reported by the ANS1512E message could have been better programmed for such high negative values, to more appropriately and helpfully report it as C0000005, which is more readily findable as a memory access problem. Your posting doesn't cite your software levels: this might be APAR IC49467. Look for event log, dsierror.log, and dsmcrash.log problem indications, and take a look at the Exchange side log if necessary.
You might also see if the backup can be invoked manually: If the same problem occurs, you can trace it thereby. Richard Sims