Something similar happened to the software bundled with my HP flatbed scanner a few years ago and I switch to VueScan. It has worked well for me since 2013 and I’ve never had to relicense, which is nice as they issue new releases quite frequently. I also like that the company is basically a father and son, no big corporation! They seem to support your machine: https://www.hamrick.com/vuescan/fujitsu_scansnap_s1500m.html#technical-information . Good luck keeping your Scansnap snapping!