DCOM issues in recent Windows updates
23.02.2018
There was an issue regarding DCOM functionality in recent Windows 10 updates. As a result, certain OPC client were not able to connect to server applications made with our Sentrol SDK.
The issue
In short, the issue was experienced by OPC client applications when these applications tried to connect to OPCEnum service or certain OPC servers. For OPCEnum, the following error message was shown:
Could not connect to OPCEnum service at 'localhost': Interface IOPCServerList not supported: Access is denied.
This message was displayed when starting the Prosys OPC Client or refreshing the server list without the ‘Registry’ option enabled.
The issue also prevented connecting to server applications made with our Sentrol SDK if the server was running as a service. In this case, the error message was:
Cannot connect to OPC Server \\localhost\Prosys.OPC.Service: Interface IOPCServerList not supported: Access is denied.
Problem resolution
After some investigations, it became clear that this issue was introduced in certain Windows 10 updates. For the 1709 version, the breaking update is KB4056892. You can easily see if the update is installed from the Control Panel. Alternatively, you an run the Winver command and verify that the Build version shows up as 16299.192.
In Windows update history the issue is formulated as “When calling CoInitializeSecurity, the call will fail if passing RPC_C_IMP_LEVEL_NONE under certain conditions”.
For 64-bit Windows machines, the fix is introduced in update KB4058258. For Version 1703, the corresponding break version is KB4056891 and the issue is fixed in KB4057144.
As a conclusion, we recommend to install the latest Windows 10 updates, and this should fix the problem automatically
Heikki Tahvanainen
Customer Service Manager
Email: heikki.tahvanainen@prosysopc.com
Expertise and responsibility areas: Prosys OPC product and service sales and customer relationships
Tags: OPC Classic, SDK for Delphi, DCOM, Delphi
comments powered by DisqusAbout Prosys OPC Ltd
Prosys OPC is a leading provider of professional OPC software and services with over 20 years of experience in the field. OPC and OPC UA (Unified Architecture) are communications standards used especially by industrial and high-tech companies.
Newest blog posts
Why Do Standards Matter in Smart Manufacturing?
The blog post discusses the importance of standards in smart manufacturing, envisioning a future where auto-configurable systems in manufacturing rely on standardized data formats for seamless integration and reduced costs, with a focus on the OPC UA standard family as a key enabler.
OPC UA PubSub to Cloud via MQTT
Detailed overview of the demo presented at the OPC Foundation booth
SimServer How To #3: Simulate data changes on a server using an OPC UA client
A two-part step-by-step tutorial on how to write data changes on an OPC UA server using an OPC UA client.