# Reported error: "operator +: nonconformant arguments (op1 is 1x8, op2 is 1x4)"

**URL:** <https://discourse.macromodelbase.com/t/reported-error-operator-nonconformant-arguments-op1-is-1x8-op2-is-1x4/273>\
**Category:** Download/Technical Issues\
**Created:** [December 25, 2025, 11:56am UTC](https://discourse.macromodelbase.com/t/reported-error-operator-nonconformant-arguments-op1-is-1x8-op2-is-1x4/273 "2025-12-25T11:56:18Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Julian\_Schuster](https://avatars.discourse-cdn.com/v4/letter/j/a587f6/32.png) [@Julian\_Schuster](https://discourse.macromodelbase.com/u/Julian_Schuster)\
**Post date:** [December 25, 2025, 11:56am UTC](https://discourse.macromodelbase.com/t/reported-error-operator-nonconformant-arguments-op1-is-1x8-op2-is-1x4/273/1 "2025-12-25T11:56:18Z")

</div>

Hi,  
I’m new here. I use Octave 9.2 and Dynare 6.2. I installed the MMB program and tried to start it. However, when I run a model, an error appears. Unfortunately, I don’t know how to fix it. I would be really grateful if someone could help me.  
Thank you for your attention.

 ![image](https://canada1.discourse-cdn.com/flex036/uploads/mmb/original/1X/9c9ab1d6658c397243438e71683be6c9cf64d967.png)