Do these cracks indicate the foundation problem of a building?
These type of cracks that run diagonally from the corners of a window are almost always caused by settling. They are very common and most of the time do not mean a continuing problem unless the cracks are open causing a measurable change in the spacing of the bricks or block. You have to look lower to determine if there is more evidence of settling at the foundation level or at the lentil of another window or door located below the window with the visible crack. Also check the interior for shifting of the window trim, plaster or drywall. Check the level and plum of the window to see if there is any movement.   In these pics, I do not see a large movement, but it is too bad the repair was not done with the same color mortar.