Everything went fine (i just had to put fastboot flash boot_a boot.img instead of fastboot flash boot boot.img because there was this error) until the very last step, when I entered
fastboot flashing lock
the Fairphone rebooted and ended up on a screen saying :
Your device is corrupt. It can’t be trusted and will not boot.
Visit this link on another device : g.co/ABH
at this point, it was impossible to do anything, and the phone was just rebooting and showing this last thing. I tried to restart it, and now the only thing it’s doing is to boot in fastboot mode. I tried everything (‘Start’, ‘Restart bootloader’, ‘Recovery Mode’, ‘Power off’), it just keeps on coming to the fastboot mode screen.
I tried unlocking the bootloader to begin again the installation, but it’s showing an error after the line fastboot flash system system.img :
Unzip the ZIP file to the folder you are operating in with the command line, then use the fastboot command there.
If you’re using Linux or macOS on the computer, you might want to add a ./ in front of it to make sure the command line uses the downloaded command instead of the older one (resulting in ./fastboot etc.).
You downloaded the ZIP file platform-tools_r31.0.3-windows.zip.
You execute the fastboot command in a command line, the command line prompt shows you in which folder you are doing that. Usually it would be in C:\Users\yourusername, but depending on what you did until now, you could be in a different folder by now. Only you know or can see that (unless you post a screenshot).
Now you have to bring the two together. platform-tools_r31.0.3-windows.zip is a ZIP archive, its contents need to go into the folder your command line shows you.
Just right-click the file in Explorer, choose extract everything (or similar) and then use the assistant coming up to extract the contents to the folder your command line shows you.
Then try to execute fastboot --version again in the command line, it should say something different than before.
It’s as good as any other folder as long as you know where it is.
Ok, let’s try it this way …
In Explorer, go to the downloaded platform-tools_r31.0.3-windows.zip and right-click it, then choose “Open with” and then “Windows-Explorer”.
Explorer should show you a folder named platform-tools then.
Now copy this folder platform-tools to C: (just drag it there with the mouse).
Press Windows + R (as in Run)
In the window that comes up then, just enter cmd and click OK. This will run cmd and open a command line.
On the command line execute cd c:\platform-tools
The command line prompt should change to c:\platform-tools> then, and now the command line will operate in that folder.