Error: 'NoneType' object has no attribute 'choices' during Crew Execution

CrewAI Community Support
1

Hi everyone,

I’m encountering an issue when running my CrewAI project and would appreciate any insights or suggestions.

Context:
I’m working on a collaborative crew setup with three agents (writer, researcher, reviewer) defined in my agents.yaml and a collaborative task in tasks.yaml. The agents use different LLMs (some via together_ai, some via openrouter).

tasks.yaml

collaborative_task:
  description: >
    Create a marketing strategy for a new AI product.

    Content Writer: Focus on messaging and content strategy
    Market Research Specialist: Provide market analysis and competitor insights
    Marketing Strategy Reviewer: Review and refine the overall strategy for clarity, effectiveness, and alignment with business goals

    Work together to create a comprehensive strategy.

  expected_output: >
    Complete marketing strategy with research backing
  agent: writer

agents.yaml

writer:
  role: >
    Content Writer
  goal: >
    Create engaging, well-structured content for marketing strategies.
  backstory: >
    You are a skilled content writer who excels at transforming research and ideas into compelling, readable marketing strategies for innovative products.
  llm: together_ai/meta-llama/Llama-3.3-70B-Instruct-Turbo-Free
  temperature: 0.7
  allow_delegation: true

researcher:
  role: >
    Market Research Specialist
  goal: >
    Provide accurate market analysis and competitor insights for new AI products.
  backstory: >
    You are a meticulous researcher with expertise in analyzing markets and competitors, delivering reliable and up-to-date information to support strategic decisions.
  llm: openrouter/deepseek/deepseek-r1-0528-qwen3-8b:free
  temperature: 0.7
  allow_delegation: false

reviewer:
  role: >
    Marketing Strategy Reviewer
  goal: >
    Review and improve the marketing strategy for clarity, coherence, and effectiveness.
  backstory: >
    You are an experienced marketing strategist, skilled at reviewing and refining marketing documents to ensure high quality and impact.
  llm: openrouter/deepseek/deepseek-r1-0528-qwen3-8b:free
  temperature: 0.5
  allow_delegation: false

crew.py

from crewai import Agent, Task, Crew

from crewai import Agent, Task, Crew
from crewai.project import CrewBase, agent, task, crew
from dotenv import load_dotenv

@CrewBase
class CollaborativeCrew():
    def __init__(self):
        load_dotenv("../.env")
        
    @agent
    def researcher(self) -> Agent:
        return Agent(
            config=self.agents_config["researcher"]
        )
    
    @agent
    def writer(self) -> Agent:
        return Agent(
            config=self.agents_config["writer"],
        )
    
    @agent
    def reviewer(self) -> Agent:
        return Agent(
            config=self.agents_config["reviewer"],
        )
    
    @task
    def collaborative_task (self) -> Task:
        return Task(
            config=self.tasks_config["collaborative_task"]
        )
        
    @crew
    def crew(self) -> Crew:
        return Crew(
            agents=self.agents,
            tasks=self.tasks,
            verbose=True
        )
        
    def run(self):
        try:
            print(self.crew().kickoff())
        except Exception as e:
            raise Exception(f"Errore durante l'esecuzione della crew: {e}")

The problem:
When I execute the code, I get the following error:

🚀 Crew: crew

└── 📋 Task: 066146a9-20a2-481d-b25f-bbb55c68e17c

Status: Executing Task...

├── 🔧 Used Delegate work to coworker (1)

├── 🔧 Used Delegate work to coworker (2)

└── ❌ LLM Failed

╭───────────────────────────────────────────────────────────────────────────────── LLM Error ─────────────────────────────────────────────────────────────────────────────────╮

│ │

│ ❌ LLM Call Failed │

│ Error: 'NoneType' object has no attribute 'choices' │

│ │

╰─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╯

Error during LLM call: 'NoneType' object has no attribute 'choices'

An unknown error occurred. Please check the details below.

Error details: 'NoneType' object has no attribute 'choices'

Questions:

  • What could cause the LLM call to return None (leading to the 'NoneType' object has no attribute 'choices' error)?
  • Is this related to the LLM provider, model configuration, or something in my YAML/task setup?
  • Are there any recommended debugging steps for this kind of error in CrewAI?