title: Ghostscript 9.18 (gswin64c.exe) crashes when -dNumRenderingThreads > 1
body: <p>I have the following problem converting a multipage pdf to tiff:</p>
  
  <pre><code>gswin64c.exe -dNumRenderingThreads=8 -dQUIET -dNOPAUSE -dBATCH -sDEVICE=tiffscaled -sCompression=g4 -r300 -o out.tiff in.pdf
  </code></pre>
  
  <p><code>in.pdf</code> is a multi-page pdf with embedded images (i.e. scanned pages).</p>
  
  <p>The command crashes (not always on the same page though) in my Windows 64 bit environment when running from the command line ("gswin64c.exe stopped working"), no STDERR is written to the console.  I use the newest Ghostscript version (9.18).</p>
  
  <p>I can do the conversion just fine ONLY if I use <code>-dNumRenderingThreads=1</code>. </p>
  
  <p>What could be the reason for this? </p>
  
  <p>EDIT: With version 9.15, the conversion runs fine, starting from 9.16 it's not working anymore.</p>
  
  <p>The System log error-entry says:</p>
  
  <pre><code>Faulting application name: gswin64c.exe, version: 0.0.0.0, time stamp: 0x56123d41
  Faulting module name: gsdll64.dll, version: 0.0.0.0, time stamp: 0x56123d3d
  Exception code: 0xc0000005
  Fault offset: 0x000000000007b930
  Faulting process id: 0x197c
  Faulting application start time: 0x01d16325677e4e24
  Faulting application path: C:\Program Files\gs\gs9.18\bin\gswin64c.exe
  Faulting module path: C:\Program Files\gs\gs9.18\bin\gsdll64.dll
  Report Id: a7fd06f0-cf18-11e5-9ab2-028037ec0200
  </code></pre>