= Troubleshooting =
[[PageOutline(2-4,, inline)]]

== Segmentation fault in Ubuntu 11.10 ==
If the reconstructor crashes like that (numbers can vary):

{{{
$ ./3dbar.sh
./3dbar.sh: line 17:  2296 Segmentation fault      python bin/reconstructor/gui.py
}}}
  
the reason can be a bug in the 'python-vtk' package installed in your system.
Unfortunately there is no automated way to fix it - you have to do it manually:

1. Find a file named 'wxVTKRenderWindowInteractor.py'. It can be located
   in '/usr/share/pyshared/vtk/wx/' directory or in similar location:
 
{{{
$ find / -name 'wxVTKRenderWindowInteractor.py'
}}}

2. Edit the file with your favourite ASCII editor. In the example editor 'vim'
   is used and it is assumed that the path to the file is
   '/usr/share/pyshared/vtk/wx/wxVTKRenderWindowInteractor.py':
 
{{{
$ sudo vim /usr/share/pyshared/vtk/wx/wxVTKRenderWindowInteractor.py
}}}

3. Near 350th line of the file find a following line:
 
{{{
                d = '_%s_%s' % (d[2:], 'void_p')
}}}

4. Add '\0' characters to the line to make it like below:

{{{
                d = '_%s_%s\0' % (d[2:], 'void_p')
}}}

5. Save the modified file.


6. The bug should be fixed for now. Try running 3dBAR again. If this solution
   doesn't work - let us know.