Invalid email address - error message at checkout

[fivetexans]

I have had a few customer come across this error message when checking out:

Invalid email address

This is after they have entered their credit card information and pressed the "Submit" button. But, the email address they entered on the previous page is valid and there isn't a place to even enter an email address on the same page where you enter your credit card information.

I use Stripe for my processor.

Any suggestions?

Thanks

[deepvyas]

Please share your store link to check the error