What does "Sorry, we have already tried texting multiple code" on Facebook mean?

[wixywax]

Facebook kept popping up with a message saying I had to verify my account by providing my number. When I finally did, I didn't receive any text, so I tried it again. Then it was saying, Sorry, we have already tried texting multiple code. Please click here for help." I waited 2/3 hours and tried again, but it keeps giving me the same error message. How long do I need to wait before I can verify my account? Or do I need to provide them with a different phone number because it's a problem with that number. Keep in mind that when I do the regular "add a number" for texting it allows me to add the number. But once I click the "Or add a number to verify your account" it repeats that same error message to me. Which doesn't make sense to me.