LE5 Reactivate Failed

I’ve been using LE5 for years and this week it stopped working.
I tried reactivating the key but it says my Serial Number does not exist. I still have my original disc and sn. All I do is edit my own voiceovers.
I’ve been waiting for a while for someone to get back to me, but it is urgent now.
Can someone else help?

Hi and welcome on the forum,

You don’t need Serial Number for the reactivation. You need the old- and new Soft-eLicenser Number only to reactivate the license from the old to the new one.