---
title: "Known issues for CGM2"
canonical: "https://help.vicon.com/space/Nexus215/11375354/Known%20issues%20for%20CGM2"
format: markdown
---
| **Issue** | **Workaround** |
| --- | --- |
| If you run a **CGM2 - Functional Calibration** pipeline operation on lower body only data, the operation fails. | Run the **CGM2 - Functional Calibration** operation on full body data only. |
| If you use a SACR marker instead of the LPSI and RPSI markers, and you try to run the **CGM2 - Functional Calibration** pipeline operation, CGM2 doesn’t work with Nexus and CGM2 calibration errors are logged. | See [Modify the Translators information](#modifyTranslators). |
| When you run a CGM2 pipeline operation in Nexus and generate a MKR file, the forearms may be poorly scaled. Also, for CGM2.4 and later, the feet may be offset. | In Polygon, manually adjust the mesh visualization segment scales. |
| You installed Nexus 2.9 or later, having previously installed CGM2 standalone (ie, pre-Nexus 2.9) and encounter issues running CGM2. | Delete this folder:  
*C:\ProgramData\pyCGM2* |
| You can't find the version number for CGM2. | See [Find the version number of CGM2](https://vicon-help.atlassian.net/wiki/spaces/Nexus215/pages/11381378/Use+pyCGM2+in+Vicon+Nexus#FindVersion). |

Note also that CGM2 is currently only a bilateral model.

For questions regarding CGM2, including the biomechanical model details and known issues, please contact Dr Fabien Leboeuf at:


[https://pycgm2.netlify.app/contact/](https://pycgm2.netlify.app/contact/)


If you have any questions regarding Vicon pyGM2, please contact [support@vicon.com.](mailto:support@vicon.com) 

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## > Macro (anchor)

Modify the Translators information

If you use a SACR marker instead of the LPSI and RPSI markers and need to run the **CGM2 - Functional Calibration** pipeline operation, to enable CGM2 to work with Nexus, you need to modify the information about the relevant markers. This information is stored in the `Translators` section of the *CGM1-pyCGM2.settings* file and the *CGM1.translators* file. To modify the information:

1. Copy the *pyCGM2 *folder from:  
*C:\Program Files\Vicon\Nexus2.#\Python\Lib\site-packages\*   
to   
*C:\ProgramData*
2. Depending on how often you use a SACR marker, edit the Translators information:
  - If you use the SACR marker by default:
    - Edit this file:  
*C:\ProgramData\pyCGM2\CGM1-pyCGM2.settings*
    - Under `Translators`, change:  
`LPSI: None` and `RPSI: None` to  
`LPSI: SACR` and `RPSI: SACR`
  - If you use the SACR marker in only some sessions:
    - Copy this file into the relevant session folder:  
*C:\ProgramData\pyCGM2\translators\CGM1.translators*
    - Edit the file as described above.