You may encounter a problem wherein when you try to connect to your instance using the Kayako Classic mobile application, the error 'Unable to log in: Failed to connect to <domain/URL>' appears. This article provides information on how to fix this problem.
The 'Unable to log in: Failed to connect to <domain/URL>' means that the mobile app could not connect to the domain or URL specified in the login screen. In most cases, you may have misspelled the URL.
The most common mistake why this error may be encountered when logging in to Kayako Classic is when you are attempting to access your Kayako Classic instance using the secure 'HTTPS' (i.e., https://brewfictus.kayako.com) request protocol instead of 'HTTP'.
Keep in mind that your Kayako Classic domain is not 'HTTPS' enabled by default. So if you have not added an SSL to it yet, then you should use 'HTTP' when accessing the instance (i.e., http://brewfictus.kayako.com/admin).
So make sure you are entering the correct URL on the login screen.