I was getting an “invalid URL” message every time I tried to share my existing registry to wedding wire. I emailed them for help and this was my response (it works!)….hope it helps someone else the way it helped me solve a frustrating issue!
“ To import your full registry URL, please highlight the URL and copy/paste it into the address bar at the top of your web browser. Go to the site, then double-click the address bar. This will expand the URL. Copy/paste this expanded URL into the import tool. ”