I am designing a 8' x 4' sign and I'm having trouble with the drop shadow.
Can someone help me resolve this issue? There are breaks in the drop shadow towards the bottom of the letters and I dont' know what's causing this. I have attached an image for reference.
If you print the sign or save the file as a PDF and open it in Acrobat does the quality of the shadow improve? If so then it is only a screen issue within Illustrator. Toggling CPU and GPU as Kurt has suggested is one way to possibly fix that.