Can't reinstall Adobe Acrobat after new hard drive installed after hard drive crash

Can anyone help? Previously had Acrobat 2015,  (purchased with a lifetime key) which automatically upgraded to 2017. My hard drive crashed and I had to have it replaced. Unfortunately the techies were not able to clone my old drive to the new one due to the damage. When I reloaded 2015 ontp mew drive it told me the serial number was invalid. I contacted tech support who walked me through reloading 2015, but when I launch it now it shuts down immediately. Would appreciate some advice on how to fix this