Dear ChimeraX users and Developers, ChimeraX v. 0.5 or 0.6 would not start on our stock Ubuntu 16.04 machines. The error message is as follows: This application failed to start because it could not find or load the Qt platform plugin "xcb" in "". Available platform plugins are: eglfs, linuxfb, minimal, minimalegl, offscreen, vnc, xcb. Reinstalling the application may fix this problem. Fatal Python error: Aborted Current thread 0x000014f406ce7740 (most recent call first): File "/usr/local/lbbs/chimerax/current/lib/python3.6/site-packages/chimerax/ui/gui.py", line 93 in __init__ File "/usr/local/lbbs/chimerax/current/lib/python3.6/site-packages/ChimeraX_main.py", line 485 in init File "/usr/local/lbbs/chimerax/current/lib/python3.6/site-packages/ChimeraX_main.py", line 788 in <module> File "/usr/local/lbbs/chimerax/current/lib/python3.6/runpy.py", line 85 in _run_code File "/usr/local/lbbs/chimerax/current/lib/python3.6/runpy.py", line 193 in _run_module_as_main Aborted (core dumped) A few more errors while checking for missing libraries (ldd) of ChimeraX-supplied libqxcb.so, libqxcb-glx-integration.so or libqxcb-egl-integration.so /usr/lib/x86_64-linux-gnu/libQt5Core.so.5: version `Qt_5.9' not found /usr/lib/x86_64-linux-gnu/libQt5Core.so.5: version `Qt_5' not found /usr/lib/x86_64-linux-gnu/libQt5XcbQpa.so.5: version `Qt_5_PRIVATE_API' not found /usr/lib/x86_64-linux-gnu/libQt5Gui.so.5: version `Qt_5' not found /usr/lib/x86_64-linux-gnu/libQt5Gui.so.5 Do I need to do a system-wide replacement of Qt5 for a different flavor (OpenGLES)? Thanks, Petr