Fix it
Find what you see, do exactly what it says. Always use the newest 1401 and Mac app from Downloads first: most problems below are fixed there. If yours is not here, or the fix did not work, send the logs (last section) and post the report ID in the Discord.
Making the stick (1401 for Windows)
“stream ended at 1048576/10485760 bytes of a chunk”
Your network closes each download connection early. 1401 1.5.0 and newer then fetch the image in small pieces, which gets under that limit, and check every piece against Apple's signed list. If 1.3 or 1.4 stopped with "(after 9 resumed connections, 8 in a row with no progress)", update 1401 and press Next again.
“disk 1 holds a macOS or Windows system partition” / “holds Mac HFS+ …”
The stick still has an old macOS installer or system on it. 1401 1.3.0 names what is on it and asks; answer Yes if nothing on that stick is needed. Older versions: Disk Management, right-click each volume on the stick, Delete Volume, then try again.
“another program is using the stick”
Close every Explorer window showing the stick, then try again.
“No MSFT_Disk objects found …”
The stick was unplugged or got a new number. Plug it in, press Refresh, pick it again.
Starting macOS from the stick
Stops at EXITBS:START on an AMD Ryzen PC
Plug the stick into the Windows PC, open 1401, choose Scan for logs and send them, and type
EXITBS:START as the last line you saw. Then build and write the stick again with the stick still
plugged in: 1401 1.3.0 switches this PC to the memory settings that got a Ryzen 5 5500 / B550 past it.
By hand (OpenCore config.plist, Booter → Quirks): DevirtualiseMmio = true,
SetupVirtualMap = true, RebuildAppleMemoryMap = false,
EnableWriteUnprotector = true, SyncRuntimePermissions = false. Change all five together.
Stops with EB.MM.AKM, “StartImage failed - Aborted” or “Couldn't allocate runtime area”
Ryzen 7000 / 9000 (AM5): restart and pick the installer again 2 or 3 times first. On these boards this stop is often random from one start to the next; several AM5 PCs that hit it once installed fine on the next start with the same stick.
If it keeps happening, keep the stick plugged in when you build again with 1401. It reads the stick's own startup log and changes the memory settings for this board one step at a time; each failed start moves it one step further. 1401 also reads the log from the stick you pick for writing, before erasing it.
Stops at “PCI configuration”
Send the logs with that line typed in; the next build adds npci=0x2000 (then 0x3000).
Also check that Above 4G Decoding is on in the BIOS.
“Still waiting for root device”
macOS cannot see the stick. Use another USB port (a USB 2 port often works), or map the ports with USBToolBox.
Firefox (or a Firefox-based browser) closes as soon as it opens
This is a known Firefox problem on OpenCore PCs, not the graphics driver: its sandbox is killed by macOS (EXC_GUARD). Safari, Chrome and Chromium-based browsers work. Use one of those for now.
RAID, RST or Intel VMD storage
macOS cannot see disks in those modes. 1401's BIOS steps page shows how to switch to AHCI / turn VMD off without breaking Windows.
The NVIDIA driver on macOS
Black screen or a looping verbose screen right after installing 1.1.0
Start macOS with the driver off (see “Remove the driver” below, or add -nvoff to boot-args), open
Terminal and run sudo chmod 644 /Library/GPUBundles/nvmtl-allow.txt, then restart. Then install the
newest driver from the Mac app; 1.2.0 and newer install that file correctly.
“Send logs” froze the Mac app
Fixed in Mac app 1.3.0: collecting takes a few minutes and the app keeps working while it runs.
The app says the driver is installed but not running
Restart once more: OpenCore applies the new SIP setting and boot-args at the next start. Still not running?
In your OpenCore config.plist, under NVRAM → Add → 7C436110-AB2A-4BBB-A880-FE41995C9F82, make
csr-active-config = 430A0000 (Data) and boot-args include nvfb=1 nvaccel=1,
and list both csr-active-config and boot-args under NVRAM → Delete for that same ID.
Reset NVRAM once from the boot picker, then start macOS.
The app is stuck at “Finding the OpenCore partition”
Update to Mac app 1.3.0. If it asks, pick the EFI partition this Mac starts from.
Two monitors: the other screen flashes or goes blank after changing resolution or refresh
Known issue we are working on. Change settings with one monitor connected, or restart after changing them.
To recover without restarting: from another computer, ssh in and run
sudo killall -9 WindowServer.
Stuck at 60 Hz, glitches in the first minute, slow cursor, an app crashes
We are fixing these from your logs. Send the logs from the Mac app right after it happens.
Remove the driver
In the boot picker choose 1401: Remove NVIDIA driver, press Y (Mac app 1.3.0 and newer ask first), then pick macOS or restart. The driver stays off, removes itself and the Mac restarts once by itself.
Sending logs
Mac: open the 1401 app → Send logs. Windows: 1401 → Scan for logs and send them with the stick plugged in; type the last line the screen showed. A PC that never reaches Windows tools: run the 1401 Probe. Post the report ID it shows in the Discord.