Already created adobe portfolio will not allow me to add new photos

I created my portfolio a month or so ago and have numerous pages which I populated by adding individual photos as well as from LR albums.  Now I can not add either a solo photo nor an album.  Always get the message: "xxx.jpg failed to upload. Please try again."  Curiously I see the photo on my screen briefly before getting the message.

Any help will be much appreciated as this is now a useless product to me.  Thanks for your help.