I had the same problem. When I upgraded KSC I observed this error. Firstly I thought to remove the task and make it again, but it wasn't solved the problem. Then I tried to make a folder directly during in the creation of the task, and I observed that if I make a folder in "C" unit I can create the task, but if I try to create the folder in other unit or in a network folder I can't create the task. Then, for me the only solution is create the folder en unit C in the same server where is installed KSC.