Try to zoom in and then grab and drag on a blank part of the diagram to recenter the diagram. If this does not work, send the output and dgm file along with your license number to firstname.lastname@example.org.
I'm running a mediation model and I just created a diagram of my model using the diagrammer. I'm a bit confused as the values displayed on the individual items of my latent variable on the diagram are different to those seen in the output under the BY estimates. Are the ones on the diagram not the factor loadings but something else?