Popular network streaming application Plex says it will end support for some LG, Vizio and Hisense smart TVs at the end of the month because those devices are not able to support certain security mechanisms.

The announcement was made in an email sent to some Plex users that was obtained by The Desk on Friday.

In the email, Plex said it would stop supporting those devices and others because they are “unable to use modern, secure connections when communicating with our services.”

Though TV sets manufactured by LG, Vizio and Hisense were specifically mentioned in the email, users of older-model TiVo DVR devices also reported receiving the message. Plex is one of a handful of apps that is natively supported on TiVo Series 3, TiVo HD and TiVo Bolt models. It was not immediately clear which of those models would lose Plex support.

The email encourages users of older devices to make the switch to a Google Chromecast, Roku or Amazon Fire TV streaming device if they want to continue using Plex’s services.