Warnings about “pniopcac.exe” after connecting to a Lock

Modified on Tue, 29 May 2018 at 08:11 PM


When connecting to a Lock from Key software, an error message about "pniopcac.exe" is displayed.


This is a specific problem that may occur after Key software update in environments having Siemens software installed.

Recommended action

Switch “PROFINET IO RT-Protocol V2.x” off from the VPN adapter:

  • Open properties of the Tosibox TAP-Windows adapter
  • deselect checkbox of following protocol: PROFINET IO RT-Protocol V2.x
  • Reconnect to Lock, warnings should not appear anymore.

If this doesn’t help, see more solutions on Siemens support site