How I fixed fastboot after Magisk update

After updating Magisk to v26.3 using the App (direct flash method), my phone only booted into the fastboot mode.

I fixed this by re-flashing the current Magisk (v26.3) using TWRP recovery. In order to do this, I needed to rename the Magisk APK to .zip (else TWRP 3.7.0 won’t recognize it). Then I flashed it, which only took a couple of seconds. After that, the phone booted normally again.

Posted by Uli Köhler in Android

How to fix “adb pair” error: unknown host service


While trying to adb pair to your device, you see an error message like

$ adb pair
Enter pairing code: 232521
error: unknown host service

and the pairing fails


You are not running the (correct version?) of the ADB server.


adb kill-server

and then retry your adb pair command.

If that doesn’t work, reboot your device.

Posted by Uli Köhler in Android

How to pair cheap Amazon “P4” gamepads with Android (Bluetooth pairing)

There are a number of nice third-party gamepads available on Amazon like this one. While the instructions tell you that in order to connect it to a PlayStation, you need to first connect it via USB, there are no instructions on how to connect it to an Android device or Laptop using Bluetooth.

First, you need to put the device into pairing mode. For my device, this worked by pressing both the Home and the Share button for approximately 5 seconds, until the LED bar started to blink.

When the LED bar blinks, you can immediately connect to the device using Bluetooth.

Note that just long-pressing the Home button made the LED bar blink but didn’t work – you need to press both the buttons circled in red.

Posted by Uli Köhler in Android

How to resolve ADB Sideload “error: closed”


You are using adb sideload to communicate with your Android device (e.g. to flash the Nexus 4 using Clockworkmod recovery), but every time you try to execute `adb sideload` you get this error message:

error: closed

Continue reading →

Posted by Uli Köhler in Android