Bootloop after Marshmallow Update

Check 1), then 2) and then 3)

  1. Dictionary Entry: Recovery Mode
  2. https://support.fairphone.com/hc/en-us/articles/201654943
  3. https://support.fairphone.com/hc/en-us/articles/207914363-Manually-install-Fairphone-OS-for-the-Fairphone-2

That should bring you up to date.