Hi there,
Like others, I'm also still having problems running TeamViewer on High Sierra 10.13.3, despite the recent fix. My iMac is only a few days old, and I updated to the security patch (10.13.3.) The installer dowloads just fine, but when I double-click to open it, the Finder bar greys-out, and just hangs - nothing happens.
I tried downloading to my old iMac with El Capitan, and it appears to work just fine. Any help is appreciated.