Unable to add passport details more than 10 years old in Canada Visitor Visa form

[Shobhit29]

I am filling a Visitor application form for my father. In the form, there is a question about US non-immigrant Visa. Since my Father has US Visa in an old passport which was expired last year. While adding the details of old passport having US visa the issue date is 25/05/2011 which is more than 10 years, so the application won't let me add this date.

I need some help to know what should i do in this case.