# 40400: Resource not found

Identifier: `not_found`



The requested resource does not exist, often because it has been deleted or the path or identifier used to reference it is incorrect.

## What you should do

Check the identifier or path used to reference the resource. The accompanying message names what wasn't found; confirm it exists and that identifiers such as the app ID or key ID are correct, including their case, since they are case-sensitive.

## Why it happens

The resource referenced by the request does not exist. It may have been deleted, or the path or identifier used to reference it may be wrong. A mismatch in the case of an identifier is a common cause.

## What you'll see

The error is reported with code 40400 and HTTP status 404. The message names the missing resource, for example a missing application or key.