Fail to login with backendless

I try to login user, but I always get
message = Invalid login or password, details = Invalid login or password, errorCode = 3003
but the user exists and 2 days ago everything was OK, I tried a lot of users

Here is the information of account:

[spoiler=“Information of account”]Backendless login videochatfacetime@mail.ru
app id 1B37D979-5E8E-ECC0-FFAE-FA3BE488E600

I try to login with:
username = @“qqq@mail.ru”;
password = @“1”;
[/spoiler]

sorry, I checked, that happens because all my users were deleted, but login works great, so I will check why these users were deleted