# opentelemetry ValueError: "Token was created in a different Context" with ParallelAgent and LlmAgent
[aabmass (maintainer)]: This is an upstream opentelemetry/cpython interaction, not an exporter bug: async iterators trip "Token was created in a different Context" after ParallelAgent sub-agents finish. If your code uses an async iterator, apply the workaround in this CPython comment: https://github.com/python/cpython/issues/118944#issuecomment-2105661088. Do not just swap start_as_current_span() for start_span(), that breaks span parent propagation.
## Context from the issue
gh:google/adk-python#860: Issue google/adk-python#860 (closed, 27 comments): When using `google.adk.agents.ParallelAgent` with multiple `google.adk.agents.LlmAgent` instances as sub-agents, `ValueError` exceptions from the `opentelemetry.context` module are consistently logged. These errors occur after each sub-agent completes its processing. While the core functionality of the agents (e.g., LLM calls and output generation) appears to be unaffected, these errors create noise in the logs and suggest a potential issue with context management within the ADK framework or its interaction with `opentelemetry`. **Steps to Reproduce:** 1.