You may have seen the yellow square or box within your sketch before. There are no additional indicators such as a message or relations symbol, and it may appear alarming as SOLIDWORKS warnings are indicated by yellow elements.
The Yellow Box symbol simply indicates that an arc or line has been reduced to a point when it has been offset. In the example below, we have a sketch with fillets (arcs). When we offset the sketch inwards at a certain distance, SOLIDWORKS minimizes the arc to a point and a yellow box appears as such indicator.
If you were to offset this point outwards, the point expands to become the arc or line.
For further technical support please contact Hawk Ridge Systems at 877.266.4469 for the U.S. or 866.587.6803 for Canada.