Connection to user authentication services is failing. There are several possible causes
If you have already installed the root certificate4, and your connection is still failing, it's possible that you are using firefox. Firefox browser has an issue with the certificate chain, but refuses to reveal what the issue actually is.
Chatment uses a root certificate managed by Chatment to identify valid services.
To automatically install this certificate, Click this link.
A copy of this root certifcate can be Downloaded here. May require saving link contents.
After Android 19(KitKat), clicking on the link to download the certificate will automatically prompt you to install the new root certificate as a trusted certficate. For older versions, instructions can be found here. or here. This will require you to set a PIN on your device if you do not already have some homescreen security set. After the new root ceriticate is installed, you can disable the PIN.
The above automic install certificate link will download a batch file that will request administrator access and then install the certificate using builtin windows certutil.exe utility.
Clicking on the download link above will launch firefox certificate manager. Check the box for 'Trust this CA to identify websites'.
For firefox you will have to use firefox's builtin certificate manager to install the certificate. Use the download link above...
This Stack Exhange Link has information about enabling self-signed/installing forieng root certificates.