ADB bricked android doesn't connect to pc I have a bricked android BLUBOO X2. I rooted it, changed build.prop to set some settings so that I could boot in Ubuntu Touch(which didn't work). And now I can't boot up anymore at all, it is in boot loop.

I tried booting in recovery and then selected "apply update from ADB". It then says: 'Now send the package you want to apply to the device with "adb sideload &lt; filename>" ... '. I did this once and it showed an error, but the weird thing/problem is that I cannot sideload anything anymore: 'error: device not found'. 

I (think I) know it is connected with my (Windows 10) PC because it made a connection and deconnecting sound when booting in recovery.

How can I get my android to be connected or how otherwise can I load a ROM or change the build.prop back?
Well, you've just messed with the system partition, so there's nothing much to panic.. Here's a stock ROM for your phone:

http://www.needrom.com/category/bluboo/x2-bluebo/ (Choose the ROM for the SAME android version you had before bricking).

The good news is you won't need to lose your data. Everything will be safe.

Download SP Flash Tools, load the scatter file from this ROM, uncheck all the partitions except ANDROID (SYSTEM) as this is the only partition you need to rectify. Click on Download and connect your device. Your device will be unbricked without having to lose any data.