Download latest Android Lollipop 5.1 stock firmware for Ulefone Vienna smartphone from here or here. Download previous firmware from here.
Archive name: Android 5.1_ulefone Vienna_20160830-ota
Archive file size: 791 MB
Image: Android 5.1_ulefone Vienna_20160830-ota.zip
Support: Mediatek MT6753
Build number: alps/full_wtk6753_65u_m0/wtk6753_65u_m0:6.0/MRA58K/1472540351:user/test-keys
Caution: Please do not update firmware unless you know what you are doing, you really want it or it is absolutely necessary. Firmware updates may occasionally have bad results, like bricking your device, temporarily or permanently. The firmware update process is done entirely at your own risk. Before attempting to update the firmware, back up your data.
Don’t miss any of our future video tutorials, follow us on Youtube. Like us on Facebook. Add us in your circles on Google+. Watch our photo albums on Flickr. Subscribe now to our newsletter.