The icons don’t work on the Top bar or

Hello, I’ve just installed startup pro and in the early stages of setting up a homepage but the customizer won’t allow me to change the icons next to the contact number, address, email etc. in the top bar menu (or any of the other sections) it comes up with a invalid request message and won’t let me save the changes.

Can you advise what the conflict would be? I’ve not installed any other plugin other than those supplied with the theme.

Thanks, Dave