Download latest KitKat stock firmware for Umi C1 phablet from here or here. Download previous stock firmware from here. You can download another Umi firmware from here.
Firmware: UMI C1 MTK6582- 174621-20140927
Update file name: UMIC1.V2.08
Update file name: UMIC1.V2.08
Archive size: 390 MB
Model: Umi C1 phablet, not Cross!
Model: Umi C1 phablet, not Cross!
Config_version: V1.1.1
Platform: Mediatek MTK6582
Project: eastaeon82_wet_kk
Config_version: V1.1.1
Baseband: MT6582_S00_MOLY_WR8_W1315_MD_WG_MP_V34_1_wg_n
Config_version: V1.1.1
Baseband: MT6582_S00_MOLY_WR8_W1315_MD_WG_MP_V34_1_wg_n