The best solution to this problem on DESKTOP is to go to forms, locate schedule C, then click on step-by-step in the top right corner and the first question it asks you should be ticked NO. This will solve the problem with the error associated with Schedule C Part K. Not sure about how to fix it on TurboTax Online.. But I do know it has something to do with the questions you are asked, be sure to answer these questions carefully in regards to your business and you should be fine, if not, play around with the yes and no answers and the error should clear, good luck!
