# XDMF & HDF input: Trouble specifying an empty DataItem
**URL:** https://discourse.paraview.org/t/xdmf-hdf-input-trouble-specifying-an-empty-dataitem/1368
**Category:** ParaView Support
**Created:** [February 27, 2019, 11:56pm UTC](https://discourse.paraview.org/t/xdmf-hdf-input-trouble-specifying-an-empty-dataitem/1368 "2019-02-27T23:56:26Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@manopapad](https://discourse.paraview.org/u/manopapad)
#### Post date: [February 27, 2019, 11:56pm UTC](https://discourse.paraview.org/t/xdmf-hdf-input-trouble-specifying-an-empty-dataitem/1368/1 "2019-02-27T23:56:26Z")
I have a particle simulation that dumps snapshots in HDF format, and I’m trying to visualize them in Paraview 5.5 through an XDMF file.
It so happens that there are no particles in the domain on the first timestep, thus my first HDF file is empty (the metadata for the fields are otherwise correct, e.g. when I open the HDF file in hdfview the velocity field is reported as a 0x3 array). I’ve been trying to convince Paraview to visualize it, but no matter what I try there’s always some mysterious error message.
Here is my current approach:
[particles.xmf](https://discourse.paraview.org/uploads/default/original/2X/b/b1832289e10bf6f794db3f2855a4e2b69eb38355.xmf) (2.6 KB)
[particles0000000001.hdf](https://discourse.paraview.org/uploads/default/original/2X/3/342c778ba8f4781b7e4d94090b700c1b397055da.hdf) (246.2 KB)
[particles0000000000.hdf](https://discourse.paraview.org/uploads/default/original/2X/5/565360ba300b24af6bc29acd82c6e43703b5d01b.hdf) (2.2 KB)
and here’s the error I’m currently getting:
XDMF Error in /home/buildslave/dashboards/buildbot/paraview-pvbinsdash-linux-shared-release\_superbuild/build/superbuild/paraview/src/VTK/ThirdParty/xdmf2/vtkxdmf2/libsrc/XdmfGrid.cxx line 760 (Error in Update() of Geometry)
ERROR: In /home/buildslave/dashboards/buildbot/paraview-pvbinsdash-linux-shared-release\_superbuild/build/superbuild/paraview/src/VTK/IO/Xdmf2/vtkXdmfReader.cxx, line 421
vtkXdmfReader (0x5cfdd90): Failed to read data.
ERROR: In /home/buildslave/dashboards/buildbot/paraview-pvbinsdash-linux-shared-release\_superbuild/build/superbuild/paraview/src/VTK/Common/ExecutionModel/vtkExecutive.cxx, line 784
vtkPVCompositeDataPipeline (0x5f608f0): Algorithm vtkFileSeriesReader(0x5f666c0) returned failure for request: vtkInformation (0x5d2c460)
Debug: Off
Modified Time: 286832
Reference Count: 1
Registered Events: (none)
Request: REQUEST\_DATA
FROM\_OUTPUT\_PORT: 0
ALGORITHM\_AFTER\_FORWARD: 1
FORWARD\_DIRECTION: 0
If I remove the block for iteration 0 the visualization works without a problem. Am I doing something wrong in the way I’m specifying an empty DataItem, or should I be doing something else altogether?
I’m using Paraview 5.5 on Linux, specificaly the binary release ParaView-5.5.0-Qt5-MPI-Linux-64bit.
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [March 4, 2019, 12:55pm UTC](https://discourse.paraview.org/t/xdmf-hdf-input-trouble-specifying-an-empty-dataitem/1368/2 "2019-03-04T12:55:58Z")
Looks like a bug in the XMF reader.