Subsystem Record could not be submitted

We have a custom UBE submitting R47500 and on occasion we are getting an error in the log "Subsystem Record could not be submitted". It appears to try and submit multiple times and then does finally submit the job successfully, however, we suspect we are losing some data when this occurs.  Most runs of this custom UBE do not produce this issue and processes the data completely. What does this message indicate?  Thank you