Hi! try to re-format your SD card to be portable storage (not internal storage) and report back if this fixes your issue.

Hello Admin,

Please, 
Could you  share a link for the flashable version 20180426 ? Thanks.

If your phone was rooted, it will not OTA update.
The latest version is flashable!

I know what you say ... 
The last flashable complete version is currently 20180330 and the last OTA update is 20180426 ... (for various reasons many users never receives OTA updates)
In my case, i need a complete 20180426 version flashable !

bvbw wrote:

I know what you say ... 
The last flashable complete version is currently 20180330 and the last OTA update is 20180426 ... (for various reasons many users never receives OTA updates)
In my case, i need a complete 20180426 version flashable !

Asked tech team about that 

Thank you Admin. Waiting for it now ...

OTA worked for me. Not sure what changed though.

Когда будет OTA для прошивки 20170708 ???
Как я могу обновить до последней прошивки без компьютера ???
Почему вы снова бросили половину своих пользователей ???
Не у всех есть возможность обновиться через USB-накопитель

When will OTA be for firmware 20170708 ???
How can I upgrade to the latest firmware without a computer ???
Why did you again throw half of your users ???
Not everyone has the opportunity to update through the USB flash drive

hayato wrote:

I tried to update by OTA, but failed.
Droid lay down.
Does anyone know why?

Version number:BV6000_Blackview_V01_20170412_20180427-1445
Version size:56.65MB
Release date:2018-04-26

I got a failed network initially but the second update try worked