WSJT-X version 2.1.2 has been released.

WSJT-X 2.1.2 GA Release
By K1JT, Joe Taylor
An error crept into the latest Hamlib code and broke the WSJT-X rig-control features for certain Icom radios. We are therefore releasing WSJT-X Version 2.1.2, which replaces the Version 2.1.1 released yesterday.
If you had rig-control problems with v2.1.1 you should definitely upgrade to v2.1.2. Others might as well do so also, though you will likely see no differences compared to v2.1.1.
A list of program changes in v2.1.2 relative to WSJT-X 2.1.0 can be found in the top two sections of the cumulative Release Notes:
Upgrading from earlier versions of WSJT-X should be seamless. There is no need to uninstall a previous version or move any files.
Links to installation packages for Windows, Linux, and Macintosh are available here:
You can also download the packages from our SourceForge site: It may take a short time for the SourceForge site to be updated.
WSJT-X is licensed under the terms of Version 3 of the GNU General Public License (GPL). Development of this software is a cooperative project to which many amateur radio operators have contributed. If you use our code, please have the courtesy to let us know about it. If you find bugs or make improvements to the code, please report them to us in a timely fashion.
We hope you will enjoy using WSJT-X Version 2.1.2.
— 73, Joe, K1JT, for the WSJT Development Group