After version 4.x, the developer (CodeIndustry) switched to subscription-based licensing . Older perpetual registration codes do not work on v5/v6.
and technical support. After this period, you can continue using your current version or renew the license at a 50% discount to receive another year of updates. Troubleshooting After version 4
(Assumes you already installed the official .deb/.rpm or downloaded binary from the vendor.) After version 4.x
: Launch Master PDF Editor from your application menu or terminal. After version 4