Error "Type password to decrypt storage" known as "Ebola" occurs on almost all Sony Xperia M / M2 C1905 / C2005.
Generally caused by Sandisk eMMC failure.
Here is step by step how to repair.
Replacing eMMC using Samsung KMVTU000LM-B609, or any emmc BGA 153 and upgrade the internal storage to 16 GB.
▫ Backup 512MiB, or Security partition only using ISP direct connection.
▫ Prepare new blank eMMC, restore backup, don't forget to Resize "User Data" & Realign Partitions".
▫ Assembly the phones, flashing using Sony Flashtool with Exclude PARTITION
▫ After Device fully On, factory reset the device.
https://www.youtube.com/watch?v=265uKKCRH6I
