Contam-EnergyPlus Co-simulation Error - Function ContamFMU_fmiGetVersion not found in FMI functions library

[Muthukumar Maragathamayil]

Hi,

I am trying to run a Contam-EnergyPlus co-simulation (Contam version - 3.4.0.6, EnergyPlus-9.1). However, the co-simulation crashes with the following error message

** Severe  ** ExternalInterface/InitExternalInterfaceFMUImport: Error when trying to
   **   ~~~   ** load FMI functions library of instance
   **   ~~~   ** "ContamFMU" of FMU "ContamFMU.fmu".
   **   ~~~   ** "Chec".
   **  Fatal  ** ExternalInterface/StopExternalInterfaceIfError: Error in ExternalInterface: Check EnergyPlus *.err file.

Could this be due to compatibility issues between Energyplus version and the FMU created by Contam3DExport? Or am I missing something?

Any advice would be much appreciated.

Thanks and regards,

Muthu

[William Dols]

It's difficult to tell from the error message.

Share the following files, and I will look into your issue:

• The original CONTAM PRJ file used to generate the FMU file using 3DExporter
• Files generated by 3DExporter: IDF file, modelDescription.xml, and contam.vef
• Other input files you are using, e.g., EPW, CTM
• ERR file generated by EnergyPlus

- Stuart

[Muthukumar Maragathamayil]

Dear Stuart, Thanks for offering to take a look into my issue.

Attached are the files as requested.

BR,

Muthukumar

[Dols, William Stuart (Fed)]

Muthukumar,

It looks as though your windows are not fully contained within the walls on which they are placed.
Read about Windows in the EnergyPlus-CONTAM Coupling Process section of the CONTAM User Guide.

 

I could not work with the PRJ without the CVF file it references, so I had to create a CVF file that would allow me to edit the PRJ with ContamW.
A quick review of the PRJ reveals that you may be using the CVF file to schedule zone temperatures.
This goes against the purpose of co-simulation with EnergyPlus, in which EnergyPlus determines indoor temperatures.

The PRJ also references a WTH file, which should not be used when performing co-simulation with EnergyPlus.
Instead, co-simulation will use the EPW file.

You need to simulate complete days, starting and ending at 00:00:00 and 24:00:00, respectively.
It’s best if your CTM and CVF files do the same.

Start by correcting these errors and see how it goes.
- Stuart

 

From: Muthukumar Maragathamayil <muthukumar.mara...@gmail.com>
Sent: Tuesday, February 3, 2026 3:57 PM
To: CONTAM <con...@list.nist.gov>
Cc: Dols, William Stuart (Fed) <willia...@nist.gov>; muthukumar.mara...@gmail.com <muthukumar.mara...@gmail.com>
Subject: [EXTERNAL] Re: Contam-EnergyPlus Co-simulation Error - Function ContamFMU_fmiGetVersion not found in FMI functions library

 

You don't often get email from muthukumar.mara...@gmail.com. Learn why this is important

[Muthukumar Maragathamayil]

Dear Stuart,

I have made the suggested modifications, but encounter the same error. Attached are the updated files.

I encountered the same error when trying to run the Sample file - MediumOffice.

Looking forward to your suggestions that could help understand the error and the cause,

Regards,

Muthukumar

[Dols, William Stuart (Fed)]

Muthukumar,

I was able to run your model once the CTM file was corrected.
If you run your model first with ContamW directly, you will see this error:

 

You can also see this error in the contam.xlog file after the co-simulation aborts:

 

As well as the following error in the ContamFMU.log file:

[Muthukumar Maragathamayil]

Dear Stuart,

I have made the necessary modifications to the ctm file and was still not able to run the simulations. I still get the error "Unable to load FMI functions library". 

I believe it has something to do with the software side of things. Initially I was using the 64-bit version of EnergyPlus 9.1, and then tried using the 32-bit version as well. 

I am assuming a library, maybe a specific file or supporting installation such as a specific version of C++ (I am currently using the 2022 version) or maybe similar such dependecy installation is required which my device is missing.

Any insights would be greatly appreciated.

Regards,

Muthukumar 

[Dols, William Stuart (Fed)]

Muthukumar,

As noted on the CONTAM 3D Exporter download page, it is a 64-bit program, as are the contamx3.exe and ContamFMU.dll that are packaged with it.
Therefore, the 64-bit version of EnergyPlus should be used.

contamx3 and ContamFMU are 64-bit programs that were built using Visual Studio 16-2019.
You can download the 64-bit redistributable runtime for this version of VS from the following website:
https://learn.microsoft.com/en-us/cpp/windows/latest-supported-vc-redist?view=msvc-170

- Stuart

 

From: Muthukumar Maragathamayil <muthukumar.mara...@gmail.com>
Sent: Monday, February 9, 2026 11:36 PM
To: CONTAM <con...@list.nist.gov>
Cc: Dols, William Stuart (Fed) <willia...@nist.gov>; CONTAM <con...@list.nist.gov>; Muthukumar Maragathamayil <muthukumar.mara...@gmail.com>
Subject: Re: [EXTERNAL] Re: Contam-EnergyPlus Co-simulation Error - Function ContamFMU_fmiGetVersion not found in FMI functions library

 

Dear Stuart,

 

I have made the necessary modifications to the ctm file and was still not able to run the simulations. I still get the error "Unable to load FMI functions library". 

 

I believe it has something to do with the software side of things. Initially I was using the 64-bit version of EnergyPlus 9.1, and then tried using the 32-bit version as well. 

 

I am assuming a library, maybe a specific file or supporting installation such as a specific version of C++ (I am currently using the 2022 version) or maybe similar such dependecy installation is required which my device is missing.

 

Any insights would be greatly appreciated.

 

Regards,

Muthukumar 

On Thursday, February 5, 2026 at 12:47:26 AM UTC+11 Dols, William Stuart (Fed) wrote:

Muthukumar,

I was able to run your model once the CTM file was corrected.
If you run your model first with ContamW directly, you will see this error:

 

You can also see this error in the contam.xlog file after the co-simulation aborts:

 

As well as the following error in the ContamFMU.log file:

 

- Stuart

 

From: Muthukumar Maragathamayil <muthukumar.mara...@gmail.com>
Sent: Tuesday, February 3, 2026 9:26 PM
To: Dols, William Stuart (Fed) <willia...@nist.gov>
Cc: CONTAM <con...@list.nist.gov>
Subject: Re: [EXTERNAL] Re: Contam-EnergyPlus Co-simulation Error - Function ContamFMU_fmiGetVersion not found in FMI functions library

 

Dear Stuart,

 

I have made the suggested modifications, but encounter the same error. Attached are the updated files.

 

I encountered the same error when trying to run the Sample file - MediumOffice.

 

Looking forward to your suggestions that could help understand the error and the cause,

 

Regards,

Muthukumar

 

On Wed, Feb 4, 2026 at 10:04 AM Dols, William Stuart (Fed) <willia...@nist.gov> wrote:

Muthukumar,

It looks as though your windows are not fully contained within the walls on which they are placed.
Read about Windows in the EnergyPlus-CONTAM Coupling Process section of the CONTAM User Guide.

 

[Muthukumar Maragathamayil]

Thanks for the very prompt clarifications, as always, Stuart.

Finally, could you offer suggestions/guidance on what could be the reasons I am getting the error "Unable to load FMI functions library" when using Energyplus 9.1.0 (64-bit version), with the required C++ redistributable version installed? If there are any further dependencies to be satisfied, kindly let me know

Thanks in advance.

Best regards,

Muthukumar

[Muthukumar Maragathamayil]

Hi Stuart,

Thanks for your suggestions, I believe trying to run the simulations from onedrive was creating the issue. I created a temporary folder on c: as you suggested, corrected the other issues you pointed and the simulation ran successfully without errors. Thank you so much for your guidance.

Best regards,

Muthukumar

On Fri, Feb 13, 2026 at 9:45 AM Dols, William Stuart (Fed) <willia...@nist.gov> wrote:

Muthukumar,

I have also experienced intermittent problems when running co-simulations on OneDrive.
Try creating a temporary run directory, e.g., “c:\_sim”, and running your simulation there.

Try running one of the demo cases within the sim folder.

 

Of course, the other issues I pointed out must also be corrected.

 

- Stuart

 

From: Dols, William Stuart (Fed)
Sent: Thursday, February 12, 2026 9:11 AM
To: 'Muthukumar Maragathamayil' <muthukumar.mara...@gmail.com>
Subject: RE: [EXTERNAL] [contam] Re: [EXTERNAL] Re: Contam-EnergyPlus Co-simulation Error - Function ContamFMU_fmiGetVersion not found in FMI functions library

 

Muthukumar,

As I indicated in a previous email, you must run simulations for complete 24-hour days.

 

 

This is also the reason I asked for the ContamFMU.log file.

The error is indicated within this file.

 

 

The EnergyPlus screenshots and ERR file do not really help, because, as I indicated previously, the way these errors manifest in EnergyPlus is beyond CONTAM’s control.

This is why the xlog and log files are needed.

 

You must fix the contam.prj file, and package it back into the ContamFMU.fmu file.

I use a tool like 7-zip to perform this operation, and associate the .fmu extension with this tool to make it easier to perform this operation.

 

- Stuart

 

From: Muthukumar Maragathamayil <muthukumar.mara...@gmail.com>

Sent: Wednesday, February 11, 2026 9:28 PM
To: Dols, William Stuart (Fed) <willia...@nist.gov>

Subject: Re: [EXTERNAL] [contam] Re: [EXTERNAL] Re: Contam-EnergyPlus Co-simulation Error - Function ContamFMU_fmiGetVersion not found in FMI functions library

 

Hi Stuart,

 

I have shared the requested files on Google drive. The contam.xlog and ContamFMU.log files were not generated when I ran the simulation. I have attached screenshots of all the error messages I get when I ran the simulations. Looking forward to your suggestions,

 

Thanks and best regards,

Muthukumar

 

On Thu, Feb 12, 2026 at 12:36 AM Dols, William Stuart (Fed) <willia...@nist.gov> wrote:

Muthukumar,

Perhaps you can share the exact files that result in the error, including the .fmu file, via Google Drive.

I am not yet convinced that the problem is not in the input files.

In the meantime, you can send me the .err, contam.xlog, and ContamFMU.log files.

 

- Stuart