I have successfully logged into https://login.teamviewer.com/ and can see my computers. When clicking "CONNECT", a popup shows the below
Please download and install TeamViewer client for best user experience and performance If you don't use TeamViewer, you can use the Web client alternatively.
•Download and install TeamViewer full version
and then click here to connect
Or use the Web client
Always use the Web client (not recommended)
I am using a PC where I cannot install the full version ov TV. But clicking "Connect" does nothing and there is no "OK" button. Even if the checkbox for "Always use web client" is ticked. This is on multiple browsers (IE/Edge/Chrone and Firefox)