I have a local webdav server running under IIS (although we discovered the problem when running our own webdav server). Starting last week ( and following an update to office ) Word crashes when we try to open a document directly from the webdav file system (by double clicking in explorer). We can open the file(s) by copying them from webdav locally and then opening them in Word.
Word seems to load the document from webdav - but then goes on to look for 2 dll's - AppVIsvStream32.dll and c2r32.dll - after which Word (or some sub process/thread of it) crashes with the error 'Word experienced an error trying to open the file' and the document fails to load. The main WinWord.exe process does, however, continue to run.
Word will, however, load the same document directly from a sharepoint server that we have on our domain.
I've added the webdav uri (http://localhost/webdav) to words trusted locations in the the trust center settings - still falls over.
I can force the document to load by turning off protected view - but obviously that's not something that we want to get users to do.
Here is an excerpt from my local iis log (which if you've used webdav before you'll see looks pretty normal - except from the requests for 2 dll's at the end - i've also tried adding the dll's and word actually loads at least one of them - which seems like a slight vulnerability) - anyway - the log :
2015-11-09 12:37:16 ::1 OPTIONS /webdav/ - 80 - ::1 Microsoft+Office+Word+2014+(16.0.6001)+Windows+NT+10.0 - 401 2 5 0
2015-11-09 12:37:16 ::1 OPTIONS /webdav/ - 80 DOMAIN\user ::1 Microsoft+Office+Word+2014+(16.0.6001)+Windows+NT+10.0 - 200 0 0 0
2015-11-09 12:37:16 ::1 LOCK /webdav/test1_webdav.docx - 80 - ::1 Microsoft+Office+Word+2014+(16.0.6001)+Windows+NT+10.0 - 401 2 5 0
2015-11-09 12:37:16 ::1 LOCK /webdav/test1_webdav.docx - 80 DOMAIN\user ::1 Microsoft+Office+Word+2014+(16.0.6001)+Windows+NT+10.0 - 200 0 0 0
2015-11-09 12:37:16 ::1 GET /webdav/test1_webdav.docx - 80 - ::1 Microsoft+Office+Word+2014+(16.0.6001)+Windows+NT+10.0 - 401 2 5 0
2015-11-09 12:37:16 ::1 GET /webdav/test1_webdav.docx - 80 DOMAIN\user ::1 Microsoft+Office+Word+2014+(16.0.6001)+Windows+NT+10.0 - 304 0 0 0
2015-11-09 12:37:16 ::1 PROPFIND /webdav/test1_webdav.docx - 80 - ::1 Microsoft+Office+Word+2014+(16.0.6001)+Windows+NT+10.0 - 401 2 5 0
2015-11-09 12:37:16 ::1 PROPFIND /webdav/test1_webdav.docx - 80 DOMAIN\user ::1 Microsoft+Office+Word+2014+(16.0.6001)+Windows+NT+10.0 - 207 0 0 0
2015-11-09 12:37:16 ::1 UNLOCK /webdav/test1_webdav.docx - 80 - ::1 Microsoft+Office+Word+2014+(16.0.6001)+Windows+NT+10.0 - 401 2 5 15
2015-11-09 12:37:16 ::1 UNLOCK /webdav/test1_webdav.docx - 80 DOMAIN\user ::1 Microsoft+Office+Word+2014+(16.0.6001)+Windows+NT+10.0 - 204 0 0 0
2015-11-09 12:37:17 ::1 PROPFIND /webdav/AppVIsvStream32.dll - 80 DOMAIN\user ::1 Microsoft-WebDAV-MiniRedir/10.0.10240 - 404 0 2 0
2015-11-09 12:37:17 ::1 PROPFIND /webdav/c2r32.dll - 80 DOMAIN\user ::1 Microsoft-WebDAV-MiniRedir/10.0.10240 - 404 0 2 0
Three of us have already spent some considerable time looking at this and have tried almost everything you could think of, compared network traces, explored winwords process, debugged it (the exception never gets back to the debbuger) etc, etc.