Moving from 10.13.6 to 10.15 is a major system overhaul. The installer completely rewrites your system partition and upgrades the file system structure (though you’re already on APFS if you updated High Sierra after a certain point). Here’s how to prepare.
: Catalina does not support 32-bit apps . Use a tool like Go64 to identify older software that will stop working after the update. how to update macos high sierra 10.13.6 to 10.15
You installed 10.15.0 (or 10.15.1 depending on which installer you got). But the final version of Catalina is . Critical security and stability patches came later. Moving from 10
: You need at least 15–20 GB of available storage. how to update macos high sierra 10.13.6 to 10.15
Typically 45–90 minutes depending on drive speed (HDD vs. SSD).
If you have a firmware password set: