SharePoint Links do not open the Word or Excel data anymore

Hello everyone, 

I have 2 SharePoints. One of them stores my word and excel documents. The other one has the links as a list to these word and excel documents. Until up to one week ago I was able to click on the link and it would open me the word document. Now it opens it as a very small image. (Please view attachment). What happened? How can i make it work again?

Best regards