Error Code 100057

Im trying to transfer files and every time I do I get an error code 100057 after some time…
Some files will copy and then it gives me the error and the drobo unmounts automatically.

Please advise…

Drobo 5n2 directly into iMac 10.15.4

Screen Shot 2020-04-30 at 6.16.04 PM

These links may help:


and (with an advert):


Run a disk utility over your Drobo files as well - my Drobo generates quite a few directory issues over time.