# BarForces.GetMaxValuesList operation failed. objet reference not set to an instance of an object dynamo

**URL:** <https://forum.dynamobim.com/t/barforces-getmaxvalueslist-operation-failed-objet-reference-not-set-to-an-instance-of-an-object-dynamo/89812>\
**Category:** Robot Structural Analysis\
**Tags:** dynamo\
**Created:** [May 19, 2023, 1:00pm UTC](https://forum.dynamobim.com/t/barforces-getmaxvalueslist-operation-failed-objet-reference-not-set-to-an-instance-of-an-object-dynamo/89812 "2023-05-19T13:00:49Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![anas.bentounsi75](https://avatars.discourse-cdn.com/v4/letter/a/b5ac83/32.png) [@anas.bentounsi75](https://forum.dynamobim.com/u/anas.bentounsi75)\
**Post date:** [May 19, 2023, 1:00pm UTC](https://forum.dynamobim.com/t/barforces-getmaxvalueslist-operation-failed-objet-reference-not-set-to-an-instance-of-an-object-dynamo/89812/1 "2023-05-19T13:00:49Z")

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Dear Dynamo Community,

I am facing an issue in Dynamo and I am hoping to get some guidance on how to resolve it. Specifically, I am getting an error message that says “BarForces.GetMaxValuesList operation failed. Object reference not set to an instance of an object”.

I believe this error is related to the “BarForces” node in my workflow, which is not being initialized correctly before I call the “GetMaxValuesList” method. I have tried a few troubleshooting steps, such as checking the input data and confirming that the node is producing the expected output, but I am still having trouble resolving the issue.

Attached is a screenshot of the error message and a file with the workflow I am working on. If anyone has encountered a similar issue or has any suggestions for how to fix this error, I would greatly appreciate your help. Thank you in advance for your assistance.

Best regards,  
[Anas Bentounsi]

 ![Screenshot 2023-05-19 135847](https://us1.discourse-cdn.com/flex022/uploads/dynamobim/original/3X/6/8/6816efbb8e934791ed2ae1e99feb35edca819a39.png)