File Transfer is turned off – Skype for Business Server 2015 Upgrade

After upgrading from Lync Server 2013 to SfB Server 2015 we tried copying and pasting images into IM windows and got the message that File Transfer is turned off.


I logged into the Lync FrontEnd server to run the command Get-CsFileTransferFilterConfiguration and the action was set to block.


Next I started up the SfB Control Panel to look at the Global Policy for FileSharing under IM and Presence, and what I see is that nothing is blocking PNG files, or JPG files, so why can’t I send files?  I also tried allowing peer to peer file transfers under Conferencing, but that didn’t help either.


I ran wireshark on my PC when i was pasting the file/image into the typing area, weirdly enough I didn’t see any traffic going to Lync FE or Edge server, which tells me its a policy in the client that I need to update somewhere, since it isn’t even making it out of my computer.  I tested again, but send a regular text message over Skype and saw the packets go to the FE server.

Resolution: I ended up going to the Conferencing tab and modifying the Global and Desktop and Application Sharing policy to Enable peer-to-peer file transfer and then waiting for it to update and had to restart the Skype client on my PC and the users I was testing with before it started working.