OpenCore installed, now can't boot any OS

Hi guys,

I've recently torn down my old Hackintosh that I was running for years and rebuilt it. I wanted to get away from Clover and Tonymac so I went with OpenCore, following the very helpful Dortania guides.

After a bit of trial and error, I've now got it to reach the installer and successfully installed Catalina, was able to boot to it from the USB and all. Following on with the post-install process, I mounted the EFI partition from the macOS disk, nuked it, and copied over the OpenCore EFI folder from my installer USB.

Now, after rebooting, I am given a few options:

1. EFI
2. OPENCORE (external) [OP: This is my installer USB]
3. macOS_Boot [OP: The volume macOS is installed to]
4. Recovery 10.15.7
5. OpenShell.efi
6. Reset NVRAM

​

My thought is macOS_Boot is the bean, so I hit 3 and get a few lines of OpenCore startup traces, ending in:

```
Exiting efiboot
[EB|#WL|9] 0x01 0x03 22 0x09
OCB: StartImage failed - aborted
```

before getting booted back to the OpenCore menu.
Selecting 1. EFI results in black screens, but the fans do ramp up a little before eventually settling. I've left it this way for ~10 min and it doesn't budge.

I also previously had Windows 10 installed, and was able to boot to it from my UEFI, but I no longer have the Windows Boot Manager option. OpenCore doesn't seem to be able to see any Windows installation either.

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I'm sure I've done something stupid and messed things up a little. I haven't done a build with OpenCore yet - I understand this is a vague post, so not expecting the answer, but a rough steer in what to look at next for troubleshooting would be great, as I think I'm at a dead end on my own.

​

Thank you so much, what I've seen of this community is absolutely fantastic and you'll make my day even with a gentle nudge in the right direction! :)