Hello, The yellow line is a display option "Show Surface Condensation Potential." That can be turned off by unchecking the box "Show Surface..." in Calculation>Display Options.
It looked to me like your boundary conditions were off. I corrected them with my best guess in the revised file attached. Also I rotated the model to be exterior left, interior right for convention. It looked like a jamb to me, not a sill, so I changed it to Jamb in properties.
Is this getting closer to what you intend?