does not work on mobile devices

Hello, thanks for your message. We are checking this problem and will let you know soon.

Please provide information about the browsers you’ve been used on mobile?

Opera, Chrome on android
Safari, Chrome on iOS

We tried on both iOS 9.3.1 and Android 5.0, and didn’t face this problem. This error message may appears when you try to book 1 time slot twice. Please provide the data you entered on demo page test. Thanks.

I found that the error appears if an email address presentedin uppercase letters.

Just when I enter the address on mobile device – the first letter uppercase by default.

Yes, we found this bug. Thank you for reporting. We will fix it and include in the new version (should be published around 10 May).