# How to open Large vtu file in Paraview?
**URL:** https://discourse.paraview.org/t/how-to-open-large-vtu-file-in-paraview/10675
**Category:** ParaView Support
**Created:** [November 4, 2022, 7:36am UTC](https://discourse.paraview.org/t/how-to-open-large-vtu-file-in-paraview/10675 "2022-11-04T07:36:09Z")
**Posts on this page:** 1
**Showing post:** 2
### Author:  [@todoooo](https://discourse.paraview.org/u/todoooo)
#### Post date: [November 6, 2022, 10:01pm UTC](https://discourse.paraview.org/t/how-to-open-large-vtu-file-in-paraview/10675/2 "2022-11-06T22:01:17Z")
@1997best You didn’t state which OS you’re using. Windows perhaps?
There is a configuration problem when building VTK with the third party XML library, _EXPAT_, which means an incorrect stream size, type **long** , is used on 64 bit systems. For Mac and Linux it works because **long** is 4 bytes on 32 bit systems and 8 bytes on 64 bit systems, but on Windows **long** is always 4 bytes so the XML reader cannot go beyond 2Gb (the positive integral range).
> [@Error reading large VTK files in the Windows version](https://discourse.paraview.org/t/error-reading-large-vtk-files-in-the-windows-version/8199/22):
>
> Hi @vmajor A type conversion error is happening in the XML parser when the byte count passes 2^31 on Windows which results in a negative byte index. Here’s a quick and dirty fix for you to use, assuming you can do a local build, while a more rigorous solution is worked out. It won’t get you past the 4Gb file size limit on Windows but it will load past the 2Gb point. I hope that helps. vtkTypeInt64 vtkXMLParser::GetXMLByteIndex() { XML\_Parser parser = static\_cast\(this-\>Parser); #i…
[https://gitlab.kitware.com/paraview/paraview/-/issues/21145](https://gitlab.kitware.com/paraview/paraview/-/issues/21145)
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