Hi Jeff, Chimera includes its own version of Tix. When you installed Chimera did you choose to use your system Python? The installer only gives this choice if it thinks your system Python is adequate. But it doesn't do a very thorough test. If you didn't use the Chimera Python you may want to reinstall and use it. If this is not the problem, it would help us to see the strace output when starting Chimera, to see what libraries are being used: % strace chimera Thanks, Tom