Licensecert.fmcert -

LicenseCert.fmcert file is the standard license certificate used to activate Claris FileMaker Pro FileMaker Server

Simple? Assisted Install questions for an IT/FileMaker person licensecert.fmcert

Renew your subscription and download a new licensecert.fmcert.
If you believe the license is perpetual, contact vendor support; the certificate might have a hard-coded end date requiring an updated file.