Thanks for reply 
I used a widget based on search with this parameters search request : #RKC OR #NP from:RadioKC
I worked fine until yesterday evening 20:44 CET (see the previous provided link) but it has been solved.
Today since 19:54 I got the same issue : check out website here : http://rkc.noip.me (internet radio station).
But search request through website twitter.com search gives results, neither the widget for hours.
Hope it helps.
Addendum : of course I meant that the widget doesn’t provide any results through the query but through the website it works fine.