I have fixed it by doing the following:
1) Go to phpmyadmin (or where ever you manage your databases).
2) Select table wp_options (if wp_ is your prefix).
3) Find the row with option_name = siteurl
In my case I host the webpage at a local server and I save the siteurl as a relative path. This means no IP, just /myBlog. I tried to change this to an absolute path, in my case https://192.168.0.3/myBlog and woopti, it works!
It is weird though, because IE on a Windows machine was able to render the Visual box, but neither FF, Chrome or Safari on either Mac nor Windows were able to do that. Strange, but now it works.
Hope someone could use this.
/Munck
