Quartus prime no longer recognize the license file

Hello

Welcome to Intel forum. May we know, have you re-generate your license.dat file to use the Ubuntu 18.04. If not, could you help to re-generate your license file first. Generate your license in Self-Service licensing Center. Only the license administrator can re-generate the license file.

Guidance: https://fpgasupport.intel.com/AlteraLicensing/license/index.html --> Licensing Center Home --> Computer and License Files --> Select a computer to generate a new license file.

Link to demo: https://www.intel.com/content/www/us/en/programmable/support/training/demonstrations/online/licensing/onl-licensing.html

Otherwise, if you still having problem, please advise the latest generate license.dat file for checking?