Paraview 5.7 with Python 3.7 on Windows 10 crashes when trying to use CellSize filter

I am trying to apply a CellSize filter in Paraview 3.7 for windows, but Paraview crashes when I select the filter from the menu. I’ve turned on logging by using the -l flag and the last line in the log file is:

( 16.783s) [paraview ] vtkSIProxy.cxx:415 ERR| vtkSISourceProxy (0000025AD62C80A0): Failed to create ‘vtkPCellSizeFilter’. This typically means that ParaView does not know about the request class to create an instance of if. Ensure that it has been correctly wrapped using the client-server wrappers and the wrapping has been initialized. Note class names are case-sensitive. Check for typos. Aborting for debugging purposes.

I’m using version which I downloaded from

Does anyone have any idea how to fix this?

This is a bug that was introduced in ParaView 5.7. It has been fixed in master. It is not in ParaView 5.6.2 either so if you need to use that filter you can use an older version of ParaView.

Thanks for the quick reply. Do you know when the bug fix will be available in the binary releases? I have Paraview 3.6 installed already but I would like to switch to Paraview 3.7 for its compatibility with python 3.7.

Note that the latest is 5.7 and not 3.7. I believe the 5.8 release candidate process should start in a week or two with the final release hopefully coming out in a month or so after that. If you want something sooner though you can get installers for the nightly master builds at Just switch from 5.7 to nightly. The nightly version isn’t guaranteed to be as stable as an official release but generally is very stable also.

You can download a nightly binary from the download page (scroll the version up).
5.8 is about to enter the release candidate cycle, that will have the fix as well.