---
title: exceptions
sidebarTitle: exceptions
---

# `prefect.server.exceptions`

## Classes

### `ObjectNotFoundError` <sup><a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/exceptions.py#L4" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>


Error raised by the Prefect REST API when a requested object is not found.

If thrown during a request, this exception will be caught and
a 404 response will be returned.


### `OrchestrationError` <sup><a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/exceptions.py#L13" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>


An error raised while orchestrating a state transition


### `MissingVariableError` <sup><a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/exceptions.py#L17" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>


An error raised by the Prefect REST API when attempting to create or update a
deployment with missing required variables.


### `FlowRunGraphTooLarge` <sup><a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/exceptions.py#L23" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>


Raised to indicate that a flow run's graph has more nodes that the configured
maximum

