We have had several people report recent problems with RsLInx showing error messages saying "Failed to show RSWHO. There are some unknown reasons, such as: Out of memory. No enough disk space and etc. " Additional some report RsLinx saying "Failed to show RSWho. Can't access file: C:\Program Files (x86)\Rockwell Software\RSCommon\Harmony.rsh", and others say they can browse the top level Ethernet devices in RsLinx but not get to the backplane.
The culprit of all of the incidents we have seen seems to be Microsoft update KB4056892 which you can learn more about at the following link.
To determine if this is the problem, temporarily remove this update and see if RsLinx resumes operating normally.
1. Go to Control Panel. The easiest way to get there is to click on your Start Menu and type "Control Panel".
2. In the search box in the top right of the Control Panel, type "Programs and Features" and click the "Programs and Features" result.
3. Click "View Installed Updates".
4. In the search box in the top right of the Installed Updates dialog type "KB4056892".
5. Select KB4056892 then click the Uninstall button
If this solves your problem and RsLinx works properly now, see Rockwell Automation Technote 1071234 Microsoft Windows Security Updates for Meltdown/Spectre Vulnerabilities Impact