The overlay didnt work. What went wrong?
In your existing record fix the 035 9 to 035 __ $a (OCoLC)######## and save to server (or make sure you have an 035 in that format). Do not try to overlay with the OCLC record you just exported that failed. You need to look it up again in OCLC, copy over any changes, and export again. The OCLC export flag has already been set, so Aleph won’t overlay with that again. If you have a mixed up record, you will have to manually bring in the record to overlay it. Being proactive by searching for ISBN before cataloging, really saves time in the end. Then add the 035 (OCoLC) to the existing record. Then catalog your new record and it should load just fine. Every now an then I can’t explain what went wrong, but I keep finding little tricks to make it better.