A few months back I made the change to my DOCICON.xml file to enable the integration with Acrobat and Sharepoint to prompt the user to "Check Out and Open" PDF files in document libraries in Sharepoint 2013. It worked fine and as expected.
After applying CU's to Sharepoint up to October 2013, this function seems to have gone away. I verified that the DOCICON.xml settings are correct. Ex: <Mapping Key="pdf" Value="pdficon_small.png" OpenControl="AdobeAcrobat.OpenDocuments" />
I can still get the "check out..." prompt if I open the document libraries with Windows Explorer, but not when PDF's are opened directly on Sharepoint. I have a support case opened with Microsoft, but they seem to point the problem at Adobe.
I have verified that the AcroPDF.dll is on each client and is enabled in IE. The PDF files open with Acrobat, but the check out prompt is not showing up unless I open the Sharepoint library with Explorer.
Have tried different Acrobat versions (10 and 11) as well as different IE versions (9,10,11)..etc...and Windows 7 or Windows 8, but the check out function does not seem to work when opening PDF's directly from Sharepoint 2013
