On April 27th, Zoom released the latest client, version 5.0. With this new release comes security enhancements, including support for GCM encryption. GCM encryption is to be enabled on May 30th.
After May 30th, all Zoom clients on older versions will receive a forced upgrade upon trying to join a meeting, to allow the use of GCM encryption. If you use Zoom Meetings, LITS advises you not to wait, and to upgrade to the new client version, 5.0, as soon as you are able. The update is available here.
Some additional resources available from Zoom:
If you are not sure what version of Zoom you currently have installed on your computer: