---
page_type: error
code: 50391
message: "50391: Conflicting conversation modification"
level: ERROR
product: Programmable Chat
---

## Description

The requested conversation is already being added or removed from this service instance concurrently with another API request. The last request will be rejected to avoid inconsistent state.

### Possible Causes

- You might be adding a new conversation to the service instance while the conversation with the same unique name is being removed from another thread.
- You might be submitting multiple concurrent requests to add a conversation with the same unique name to the service instance.
- You might be submitting multiple concurrent requests to delete the same conversation by SID or unique name from the service instance.

### Possible Solutions

- Implement an operation retrier and repeat the failed conversation API requests after an interval of time, using an exponential backoff algorithm.
- Review your application logic that caused the race condition when adding or removing users. Perhaps the conflicting operations are happening in a loop that could be avoided.
- Serialize your API requests that add or remove conversations. Wait until the original request completes and returns an API response, before sending any successive conversation requests.