I filed my return last year by paper, and it was sent back to me to be signed, I immediately signed and mailed it again, now it won't allow me to e-file. What do I do?

It was mailed back in November, 4 months ago. It says its supposed to only take about 8 weeks, I would like to e-file this time to avoid the whole issue of dealing with postal service and the time it takes for papers to be processed.