Just 2 days after my order, ALLDOCUBE realeased I50 mini pro NFE version with L1 Widevine. And now I find out that upgrade is not possibile for preview version. Just disappointed. Surely, upgrade It is possibile by a system update. But ALLDOCUBE doesn't want! Not a good thing. Xiaomi made upgrade to Widevine L1 on many its smartphone by a system update. Just a differenti  style!