Twitter:image invalid URL

[InvestNINews]

HI

I have been trying (through googling and reading other responses) to find out why the Card Validator is saing Invalid URL for the twitter:image option.

I can navigate to the image fine…

Here is an example page from our site: http://www.investni.com/news/invest-ni--propels--60-businesses-to-success.html

I am a bit stumped and would appreciate any help.

Rodney