i'm running dbdesigner on amd64 (i don't know if happen with other archs), and seems it needs libexpat.1.so. app-emulation/emul-linux-x86-baselibs-10.2 provide /usr/lib32//usr/lib32/libexpat.so -> libexpat.so.0.5.0 Coping the file in /opt/DBDesigner4/Linuxlib (or symlink) solve this problem. Related/Similar bug... #123769
*** This bug has been marked as a duplicate of bug 135731 ***