Fedora 23 includes keepassx 2.0 (updates). However Fedora 24 contains 0.4.4. The package was downgraded during the upgrade from (23 -> 24) and now I can't open my keepassx database due to the incompatible database format. r2:yum.repos.d $ cat /etc/redhat-release Fedora release 24 (Twenty Four) r2:yum.repos.d $ rpm -qa keepassx keepassx-0.4.4-1.fc24.x86_64 $ grep keepassx /var/log/dnf.log May 13 11:06:48 DEBUG ---> Package keepassx.x86_64 2.0.0-1.fc23 will be upgraded May 13 11:06:48 DEBUG ---> Package keepassx.x86_64 1:0.4.4-1.fc24 will be an upgrade r2:yum.repos.d $ sudo dnf clean all && sudo dnf update keepassx Failed to synchronize cache for repo 'xpra', disabling. Last metadata expiration check: 0:00:03 ago on Sat May 14 17:03:02 2016. Dependencies resolved. Nothing to do. Complete!
I made an account to say this same thing. KeepassX has been downgraded to 0.4.4 in Fedora 24. They are not compatible. At the very least build them separately as Keepassx and KeepassX2 or something like that.
*** This bug has been marked as a duplicate of bug 1338054 ***