Hi Jim, The strace output you sent shows that Chimera is using the system python /usr/bin/python2.2 on your machine. That is loading the system Python Tk module (called Tkinter) and that is linked against Tcl/Tk 8.3 and Tix 8.1 while Chimera requires Tcl/Tk 8.4 and Tix 8.2. The solution here is to reinstall Chimera. I'm guessing that it asked you whether you wanted to use the system Python or the one provided with Chimera, and you elected to use the system Python. You need to use the Python provided Chimera. If the installer does not ask about which Python to use let me know. Tom