It’s sometimes when you connect to FSharing from Finder in Mac OSX, it shows the message “The operation can’t be completed because the original item for ‘On Device’ can’t be found.”. This issue happens in many reasons like you have changed networks, or experienced a drop to your connection and had to re-establish it, but may also happen because of other similar disruptions.
When this happens, the OSX Finder may still maintain its list of available shared computers, when the system has lost the network association with the system. In cases like this, the Finder should update to reflect a new link to the shared systems, or remove them if they are no longer available; however, there may be times when a hiccup or two keeps this from happening, resulting in the warning message.
To fix this problem, you simply need to relaunch the Finder, and it will re-populate the list of shared devices. To do this, hold the Option key and right-click the Finder icon in the Dock, then select Relaunch.