A friend hit me up with the screenshot below, as those who work with F5 ASM would know this is the page you see the WAF blocks your request, and there’s no way to tell from this error or the page about why your request is getting blocked.
However, since the application form is a simple straight forward text-based form, there is a high chance that you are hitting the block page due to the photograph which is also required and has some very strict requirements as mentioned on the dv program website.
I did some digging for a fix and saw that some people have fixed the issue by deleting the exif data from the image, and thought I should make a note of it here since I’m sure many around the world are going to hit this error while they submit their forms.
Removing the exif data did not alter the dpi resolution or the size and the photo was accepted by the website!
The tool which I used to remove the exif data is here – https://www.imgonline.com.ua/eng/delete-exif-result.php
Go ahead and try it!
May your American dream come true!