Are you sure you are using the genuine sitegenuine site? It ends with .gov. There are many scam sites.
Check carefully about from top to bottom about subtle error messages. Last time I had error on the address. The site has a strange validation, and it would not accept a valid address, so check in Google map (directly and other things at same address) on how to write in an alternate way the address. As you see, there are some really annoying validation. Check also foreign characters, and formatting (e.g. if you did a copy paste).
