I wonder if it has to do with the browser you are using? I just tried and it worked normally for me.
Dj: I edited your layout credits for your latest layout and linked the kit you were trying to link. I tried highlighting the link and then linked it using the link icon and I also tried just copy and pasting the link directly, both worked normally for me.
Maybe see if your browser needs to be updated? Or if you recently updated it, the new version might be causing the issue. It's hard to track down little issues like this. Especially when I can't duplicate it and produce the issue myself.
I wish I could be more helpful.