did you enter your correct social security number? that's what I would check first. if it is correct it won't help to refile. the same problem will occur. even mailing it won't help. Next, I would try accessing your social security a/c. https://www.ssa.gov/onlineservices/ you can see what the SSA has. if its records show you are dead it would presume you're an imposter. however, even if the SSA shows you're alive, you'll likely still need to visit a local office because they would need to be the ones to notify the IRS that you're alive.
call the nearest office because this will require an in-person visit to clear this up. make sure to inquire as to what forms of identification you'll need to bring. then once they verify your alive make sure that they notify the IRS of that fact.