Yesterday a new version of the MetaTrader 5 platform was released by MetaQuotes - Build 3520. It should now be available via automatic update feature in your broker's MT5. It adds two-factor authentication to the terminal and some new features to the MQL5 language:

MetaQuotes' forum announcement thread:
https://www.mql5.com/en/forum/436929
If you find a bug or some undocumented feature in the new build, please post about it here.
- Added an option to add two-factor authentication (2FA) for account access. This improves the security by requiring a code generated by Google Authenticator or similar apps.
- Fixed operation of
CopyTicsk()
function when working with custom symbols via MQL5. - Added
CL_LAST_ERROR
andCL_ERROR_DESCRIPTION
values to obtain information about errors when working with OpenCL resources. - Fixed matrix multiplication (with
matrx::MatMul
) when working with large matrices. - Fixed some other errors.

MetaQuotes' forum announcement thread:
https://www.mql5.com/en/forum/436929
If you find a bug or some undocumented feature in the new build, please post about it here.