We've had a few reports of this issue when using Klok Mobile Beta on certain mobile device browsers and browser versions. For example, we are currently looking into an issue with the sign in button for mobile devices that use the browser Opera.
We've had customers provide feedback stating they can login to Klok Mobile Beta on their mobile device if they try another mobile browser (i.e. Firefox, Chrome, Atomic, etc.). Once they login successfully using another browser on their mobile device, they're able to go back to using their preferred mobile browser and login successfully to Klok Mobile Beta.
Thank you for your patience as we look into this issue.