Can you unravel knitting after binding off if you see that you have made a mistake that needs to be fixed?

This is possible, but it is difficult if you have already made the finishing off knot. You will have to either very carefully cut the knot off and begin unraveling, or, if the knot isn't too tight, undo the knot by pulling the yarn out of the loop. Once the knot is either undone or cut off, you have simply to pull the string and the material should unravel, even the bind off edge. You may need to have a few feet of extra yarn to redo the bind off edge, especially if the original knot was cut. Just attach the extra yarn to the project at the beginning of the cast off row, and continue to work.Do not attach the yarn in the middle of a row. This will probably make a messy-looking knot in the middle of the fabric.

Hope this helped!