Gerard Ryan I think it is fine to remove the CRs if you are trying to delete them from UPS and they don't exist. Either the CR has not been processed and there never was data to delete, or the data has already been deleted.

I suppose there is also the case where UPS is down for some reason, but I don't think you will get a 404 in that scenario.

Anyway, I would delete it and not worry about it.