rEFInd upgrade on Linux/MacOS dual boot = boot partition helper error

[William Eames]

After Apple updated my MacOS Sierra (on my dual boot MacBook Pro, using MacOS + Linux), produced boot coup. I downloaded and re-installed newer version (11.4) of rEFInd. System boots perfectly to rEFInd, and thence to Linux, but attempt to boot to MacOS produces "A boot helper partition is required when working with Core Storage." No MAC partitions were deleted. Attempted MacOS reinstall using Recovery HD online, reproduces above error. Mac First Aid on MacIntosh HD logical drive reported volume OK, system check exit code = 0. Growing Logical Volume, Resizing Core Storage Logical Volume to 249,782,378,496 bytes, operation successful. Layout:
/dev/disk0 (internal, physical)
0: GUID_partition_scheme +500.1 GB disk 0
1: type EFI - name EFI 200.7 MB disk0s1
2: type Apple_CoreStorage - name MachintoshHD 250.1 GB disk0s2
3: type Apple_Boot - name Recovery HD 650.0 MB disk0s3
4: type Linux FileSystem - - 243.5 GB disk0s4
5: type Linux Swap - - 5.4 GB disk0s5

Can anyone offer a next step to get back dual boot capability?

[Roderick W. Smith]

First, check to see if you've hidden any boot loaders via refind.conf entries or the dynamic hiding feature in recent versions of rEFInd, as described here. It's possible that you've hidden the boot loader that you should (now) be using, and had been booting via one that's no longer working with the update. If that's what's happened, you should un-hide the hidden boot loader and hide the one that's now non-functional.

You can also check to see if you can boot to macOS by bypassing rEFInd, via the Alt/Option key when you start up the computer. If this works, then you at least know that macOS is working and correctly installed, and that the problem is with rEFInd. You can use this boot method while debugging the problem. If you can't boot to macOS via this method, then it's likely that the problem isn't with rEFInd itself, but with something else about your installation, like a damaged filesystem.

On systems with Apple Core Storage, which your system has, macOS boots via a helper boot loader that's normally stored on the Recovery HD volume, which your system seems to have. rEFInd should be scanning this volume. If that's not happening, then it indicates either a configuration problem or a problem with that volume -- it could be that its filesystem is damaged, for instance. (Filesystem damage would likely prevent booting via Apple's Alt/Option boot manager, too.) You could try using Disk Utility (or command-line tools) to examine and repair that partition.

One final long-shot thing you might try is to install Apples APFS EFI driver in rEFInd's drivers_x64 subdirectory. This page covers rEFInd and filesystem drivers; search it for "APFS" for information on this driver, and read the "Installing rEFInd's EFI Drivers" section for information on doing this.