The 3.15.0 services do not start on Java 21 because the shipped .jvmopts files still set -XX:MaxPermSize=512m; upgrade to 3.15.1 and follow its notes
Requires Java 21. You must uninstall Java 8 (1.8) after upgrading: sudo dnf remove 'java-1.8.0-openjdk*'. Uninstall it only after the upgrade, because older backend packages depend on it. The services start with /usr/bin/java, so check that java -version then reports 21; if it does not, select Java 21 with sudo alternatives --config java
On hosts that once ran 3.9.8 or earlier, remove the old ticrypt-backup and ticrypt-storage packages before uninstalling Java 8: sudo systemctl disable --now ticrypt-backup, then sudo dnf remove ticrypt-backup, and the same for ticrypt-storage if it is installed. Both services were retired in 3.9.9 and nothing uses them, but upgrades do not uninstall them, and because they depend on Java 8, dnf refuses to remove Java 8 while they are installed
Remove -XX:MaxPermSize=512m from every /etc/ticrypt/*.jvmopts file (sudo sed -i '/MaxPermSize/d' /etc/ticrypt/*.jvmopts), then restart the backend services. Java 21 does not recognize the option and the services fail to start; the 3.15.0 packages still ship it, and upgrades keep files you have edited
Also remove any other Java 8 option your site added to /etc/ticrypt/*.jvmopts, such as -XX:+CMSClassUnloadingEnabled or -XX:+UseConcMarkSweepGC. Java 21 rejects them and the service fails with Unrecognized VM option. java $(cat /etc/ticrypt/<service>.jvmopts) -version reports any option Java 21 rejects without starting the service. Run sudo systemctl reset-failed 'ticrypt-*' before restarting a service that systemd stopped retrying
