Can't install OTA12 on Meizu MX4

[stefwe]

Hello,

i'm running ota11 on my meizu mx4 and can not update to ota12.

Update via system settings brings the following error:

Clear the cache of system settings app don't help.
Switch to different channel like rc or dev brings up the same error.

Installing via the installer i get the following error:

error: Error: adb:format: Error: {"error":{"killed":false,"code":1,"signal":null,"cmd":"/opt/ubports-installer/resources/app.asar.unpacked/platform-tools/linux/adb -P 5037 shell echo ."},"stdout":"","stderr":"error: insufficient permissions for device: user in plugdev group; are your udev rules wrong?\nSee [http://developer.android.com/tools/device.html] for more information"}
stack trace: Error: {"error":{"killed":false,"code":1,"signal":null,"cmd":"/opt/ubports-installer/resources/app.asar.unpacked/platform-tools/linux/adb -P 5037 shell echo ."},"stdout":"","stderr":"error: insufficient permissions for device: user in plugdev group; are your udev rules wrong?\nSee [http://developer.android.com/tools/device.html] for more information"}
    at /opt/ubports-installer/resources/app.asar/node_modules/promise-android-tools/src/adb.js:66:13
    at /opt/ubports-installer/resources/app.asar/src/utils.js:282:7
    at ChildProcess.exithandler (child_process.js:319:5)
    at ChildProcess.emit (events.js:194:13)
    at maybeClose (internal/child_process.js:998:16)
    at Socket.<anonymous> (internal/child_process.js:403:11)
    at Socket.emit (events.js:194:13)
    at Pipe.<anonymous> (net.js:593:12)

i am very thankful for your help.