If the issue is still persisting, move down to the next potential fix below.
MAC COULD NOT UNMOUNT DISK FULL
MAC COULD NOT UNMOUNT DISK SERIES
If you’re comfortable with using Terminal commands, our recommendation is to follow the instructions below and create a new partition map via a series of commands: Creating a New Partition Map from the Terminal App modifying the partition map via Disk Utilityī.
You should see a similar screen to the image below – Once you see this, the problem should be resolved.
MAC COULD NOT UNMOUNT DISK FREE
Since there are 2 different ways that will allow you to do this, we’ve put together 2 different sub-guides that will walk you through the process of creating a new partition map.įell free to follow whichever one is closer to your preferred way of troubleshooting macOS issues: A. This is confirmed in situations where the Couldn’t modify partition map error is being caused by a system action that ends up corrupting the partition map. Now that you are aware of every scenario that might trigger the Couldn’t modify partition map error, here’s a list of methods that might allow you to fix it: Method 1: Creating a New Partition MapĪs it turns out, a lot of affected users that were also dealing with this issue on macOS have managed to fix the issue by using Disk Utility to create a new partition map by forcing the utility to show all devices and erasing the problematic partition. If this fails, you should attempt to mont a healthy macOS state via the Time Machine utility. In this case, you should be able to fix the issue by initiating a repair disk operation via the Recovery Menu.