"check your internet connection and try again" When trying to share a file?

I am having the same problem and I urgently need to share files with someone.

I use Dropbox all the time so I know what I am doing is correct. 

I created a folder and I clicked Share in order to share the folder with another person...

I entered the email address into the email section which turns into red coloured font when completed, and immediately beneath the email address section and above the message section a red bar appears with black font saying "Check your internet connection and try again". 

The internet is working for everything except for this, but it obviously has nothing to do with the internet. It hasn't even allowed you to try to send at this point. When you do try to send the message, it does not work.

I need to share the whole folder because there are multiple documents to share.

However, I did 2 other checks.....

The first was to see if I could share folders in my Dropbox with a new contact that I have already shared with others in the past, and I received the same error message. So nothing is sending.

The second check was to see whether I could send on an individual file within a folder, so I created a Test document within a Test folder, and I was able to send the individual document within the folder to a contact.... So there's been some kind of a block put on folders. I'd imagine someone was updating the Dropbox system and clicked the wrong button or didn't reverse their changes once they'd finished updates on the system.... I'd imagine it's an easy fix, but I'd guess the developers need to go into the folder permissions in the administrative system in order to make the change, or check the allowed permissions of certain types of Users / Customers which may have blocked them from sending Folders.