The Apple servers are not signing the specific firmware version you are trying to install.
Always use an Apple-certified MFi cable. Third-party "charging only" cables lack the data pins required to send the loader files.
The most common cause of "Loader not found" is attempting to install an unsigned or incorrect IPSW file. loader for iphone9 3d101ap not found better
Release the but keep holding Volume Down for another 10 seconds.
The screen should remain black, but your computer will say it has "detected an iPhone in recovery." Try the restore now. Step 4: Update the "Handshake" Software The Apple servers are not signing the specific
The "3D" in the error code often points to a data transmission interrupt.
This error typically triggers when the —the software that tells the hardware how to start up—cannot be located or verified by the flashing software. This happens for three main reasons: The most common cause of "Loader not found"
Are you using or a third-party tool like 3uTools to perform this update?
If you've tried different cables and verified your IPSW is signed, the method is your best bet for bypassing the 3D101AP error. This bypasses the OS entirely and talks directly to the hardware chips, forcing the loader to initialize.
If standard Recovery Mode (the "apple.com" screen) is giving you the "loader not found" error, you need to go deeper into . Connect the phone to your computer. Quickly press Volume Up , then Volume Down . Hold the Side Button until the screen goes black.