Ever seen this error while connecting to a specific Citrix XenApp 6.5 published app or desktop? Whilst other apps / desktops in the same farm works?

2015-05-06_13-18-31

 

No errors on Storefront, Web Interface or the Data Collectors, so I ran qfarm /load:

2015-05-06_13-29-35

 

I though Load Throttling Load of 2000 was a little strange in the afternoon, logonstorms over and the users are back from lunch. So I disabled logons to the problemserver and voilĂ , everything is back to normal.