paint tool can't not used properly

Problem: I am trying to edit an CT using the segment editor and the paint feature in the editor. But when I go to paint, I can’t paint my wanted content on image. no trace was showed in the image. it can’t allowed me to edit.Does anyone know how to fix this problem?

Try with the SampleData and if that works then it’s possible you are hitting this issue. If that’s not it you can post your data for others to try.