After a Windows/system update, my app (.NET 4.7.1 running on Win 7) for actuator control is no longer working. I am using Siemens WinAC ODK 4.2 in SMX mode to control a PLC connected to Festo actuators.

I now get error code 2 when calling S7SMX_Open() (via interop) in S7smxx.dll. That error code is defined as "S7SMX_ERR_NO_LOCATOR" in my program.

An older .NET app using the same library is also no longer working.

It appears to be the same error as mentioned here:

https://support.industry.siemens.com/tf/WW/en/posts/winac-odk-4-2-smx-failure-s7smx-err-no-locator/32946?page=0&pageSize=10

The main thread in the program is marked as using a single threaded apartment (STAThread).

What is causing this and how can it e fixed? I noticed that the actuators were sending a fault signal the week before - could that be related?

Where are the error codes described? I haven't found many details in the manuals so it's hard to know what is going wrong.

When I look at SIMATEC manager, it doesn't seem like the SoftPLC is running... I get a connection error when I try to read hardware or module information... 

Perhaps the Windows update caused the program to no longer start automatically...

I am trying to start the WinLC RTX manually. When I open

Start -> All programs -> Siemens Automation ->SIMATIC -> PC Based Control

the panel shows "Not connected". The "CPU" menu does not contain an option to "Start Controller".

I am now trying to uninstall and then reinstall Interval Zero RTX 2009 and Simatic WinAC RTX.

Uninstalling Simatic WinAC RTX was successful, but reported several errors.

However, I am unable to uninstall Interval Zero RTX 2009. The process hangs, and also cannot be cancelled but must be terminated in task manager.

The installer for Simatic WinAC RTX refuses to run because it detects that Interval Zero RTX 2009 is still installed.

I found an article talking about Windows 7 security updates causing problems with Interval Zero RTX:

https://www.intervalzero.com/meltdown-spectre-unsupported-updates/

I managed to uninstall everything after a few tries and rebooting.

IntervalZero RTX 2009 has now been reinstalled.

But installing WinAC RTX 2010 SP1 gives an error dialog:

s7startx

could not start "bin \rtssrun" /q /d /f s7smxvmx.rtdll

I click Cancel, but the dialog keeps reappearing and the installer is now stuck.

After terminating it in Task manager, the message:

"The program can't start because RtxProp.dll is missing from your computer"

appears.

I gave up trying to reinstall the program stack.

Instead I made a clone of an existing pc with a working soft plc.

After installing the new hard drive, the situation is exactly the same. The SIMATIC Panel says "Not connected" and the other programs show the same problems.

Hi larsped,

I think you should start a Support Request, because nobody answered you

Hope you will get a solution for your issue! And maybe you can post the solution here for the other users.

Best Regards,

Noodles

The error is fixed now.

It was caused by several Windows Update patches related to Meltdown/Spectre. These patches are incompatible with RTX 2009, causing it to stop working.

After uninstalling the patches, the system is working again.

BTW, the pc I cloned from showed the exact same symptoms after I rebooted it. But it was fixed the same way.

https://confluence.merging.com/pages/viewpage.action?pageId=25035234