Hello Mark,

With Catalina, Apple uses two volumes for the "Mac HD". One volume only has OS system files on it and the other (the "Data" one) has everything else - however this appears as a single volume and you normally can only see them as separate volumes if you look in Disk Utility. What is the problem specifically that you came across... did you get an error message with this specific installer and/or was it different than others somehow?

Also, if you click on the Mac HD icon and Get Info (command+I), how much free hard disk space does it say you have?

Last edited by Andrew - PG Music; 04/30/20 07:26 AM.

Andrew
PG Music Inc.