The cleanup circle radius is too large. Reduce the cleanup circle radii of all walls at the wall joint, or adjust the baselines so that the ends of all justification lines fall within the wall joint cleanup circle radii. 
This situation can also occur if a door, window, opening, or door/window assembly is placed too close to the end of the wall and the wall or the objects in it use elaborate endcaps. In such cases, there may not be enough room for these conditions to be drawn correctly. 
Solution tip icon displayed in a wall with a short wall segment
Solution tip icon displayed in a wall with a window near its end