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Simplinx Support

"pniopcac.exe Assertion Failed" Error

Problem

Section titled “Problem”

When establishing a remote connection, the error “pniopcac.exe Assertion Failed” appears on computers that have Siemens PLC software (e.g., TIA Portal, STEP 7) installed.

Root cause: Siemens software installs a PROFINET IO RT-Protocol on all network adapters, including the virtual Simplinx network adapter. This protocol conflicts with the connection process.

Solution

Section titled “Solution”

Removing PROFINET IO RT-Protocol from Simplinx adapter properties Network Adapter Properties — uncheck PROFINET IO RT-Protocol from the Simplinx adapter

  1. Open Control Panel → Network and Internet → Network Connections (or press Win+R, type ncpa.cpl).
  2. Locate the Simplinx Network Adapter in the list of adapters.
  3. Right-click the Simplinx adapter and select Properties.
  4. In the list of protocols/services, find “PROFINET IO RT-Protocol VX.X” and uncheck / remove it.
  5. Click OK to apply, then close the Properties dialog.
  6. Retry your remote connection — the error should no longer appear.