When I attempt to Resolved Boss/Base the enclosed sketch, Solid Works raises an error message that says "Sketch is open, self intersecting, or intersects the center line." How would one go about resolving this?
Welcome to the forum. It's difficult to say for sure without seeing the file, but I suspect that the portions of the sketch at top and bottom are sticking past the centerline, which would probably cause the error message. Make those short vertical lines collinear with your centerline and try again.
It might be better if you showed the error message as well.
Jarek,... the error can also mean there is a extra line/arc superimposed, closely overlapped or sharing a same point in your sketch.... zoom up and slowly go down the chain of and see if you can find it/them?
you can also try this tool
2015 SOLIDWORKS Help - Check Sketch for Feature Usage
While in the sketch mode, go to Tools > Sketch Tools > Check Sketch for Feature and that would find the issues for you.
Retrieving data ...