VTK outline output mangles files in some cases

Problem

Some of the written .vtu files are mangled.

      <Cells>
        <DataArray type="Int64" Name="connectivity" format="ascii" RangeMin>
          0 1 2>
          0 1 2 3 4 5
          6 7
            <DataArra        <DataA Name="offsets" format="ascii" RangeMin="8" RangeMax="8">
          8
        </DataArray>
        <DataArray type="UInt8" Name="types" format="ascii" RangeMin="11" RangeMax="11">
          11
        </DataArray>
      </Cells>

And spurious characters after </VTKFile> sometimes.

Setup

ExaMPM, OpenMPI, VTK 7.1.1, 2 Ranks, 1 Thread/rank on 8core machine.