Assertion error “pniopcac.exe” when setting up a VPN connection

26 Aug 2025
Knowledge

Problem

This error message appears when you set up a VPN connection to one of your edge gateways.

Assertion error pniopcac.png

Cause

Siemens software on your computer is causing this error.

Solution

Open the PG/PC interface either from the Windows Control Panel or from the SIMATIC Manager via "Tools > Set PG/PC Interface...".
Switch to the PNIO Adapter tab.
Disable the TAP-Windows Adapter and click OK.
Restart the computer.

Title

Assertion error “pniopcac.exe” when setting up a VPN connection

URL Name

Assertion-error-pniopcac-exe-when-setting-up-a-VPN-connection

Assertion error “pniopcac.exe” when setting up a VPN connection

Introduction

Remote Access

Fleet Management

User Management

Customer Portal

Machine Data

Notifications

Hardware

Open Innovation

Security and Availablility

Release Notes

Knowledge

Assertion error “pniopcac.exe” when setting up a VPN connection

New Section

Properties

Introduction

Getting Started

Remote Access

VPN connection

VPN Client

Web Access

Connect to your machine

Connection details

M2M Cloud Cluster

Fleet Management

Edge gateway registration

IXagent registration

WAN Settings

LAN Settings

Edge gateway firewall

General device settings

User Management

Setup

Invite and manage users

My account

External Identity And Access Management

Customer Portal

Custom login page and homepages

White labeling

Machine Data

Live Data

Historical Data

Data Source protocols

Pages, cards, and reports

Components

AI assistant

Notifications

Alarms & Notifications

Hardware

Edge gateways and accessories

Open Innovation

Custom development

Marketplace

Security and Availablility

Security

Availability

Release Notes

IXON Cloud

Knowledge

Highlighted Articles

Tips

Related Articles