title: WebDAV - Microsoft Excel 2016 not able to save back changes
body: <p>I have a set up the ITHit WebDAV server on our company website which works great on Office 2007/10/13 with PowerPoint, Word and Excel. However I have recently updated to Office 2016 and I have found that Excel no longer works, however Word and PowerPoint work OK.</p>
  
  <p>In Excel I get the error message below:</p>
  
  <p><a href="https://i.stack.imgur.com/jcW30.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/jcW30.png" alt="enter image description here"></a></p>
  
  <p>In Word and PowerPoint I get the dialog below which I can skip:</p>
  
  <p><a href="https://i.stack.imgur.com/fBMz7.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/fBMz7.png" alt="enter image description here"></a></p>
  
  <p>Is there a known issue with the ITHit WebDAV server in Excel 2016?</p>
  
  <p>There are no exceptions thrown when I'm attached in Visual Studio 2015. Also when I've checked Fiddler I can see the last thing the WebDAV server try to do is lock the document which is seems to do without any exceptions. It locked and unlocks the document twice then on the lock where I try to save it then comes back with the error message in Excel (see pic 1). </p>
  
  <p>The lock requests are shown below:</p>
  
  <p>First Lock OK:
  <a href="https://i.stack.imgur.com/lB5wU.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/lB5wU.png" alt="enter image description here"></a></p>
  
  <p>Unlock:
  <a href="https://i.stack.imgur.com/Fn4pK.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Fn4pK.png" alt="enter image description here"></a></p>
  
  <p>locks the document and stops:
  <a href="https://i.stack.imgur.com/AQMKP.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/AQMKP.png" alt="enter image description here"></a></p>
  
  <p>The only think I can see that is different is a field in the Miscellaneous section of the header:
  <a href="https://i.stack.imgur.com/ykQSw.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ykQSw.png" alt="enter image description here"></a></p>
  
  <p>I've exhausted all options and I've got no idea why this is happening with just excel in office 2016. </p>
  
  <p>Any help would be greatly appreciated.</p>