# Exceptions
<a name="query-exceptions"></a>

The following table lists query-side exceptions that could be encountered while using a query.


| Neptune Analytics error code | HTTP status | Retriable | Description | 
| --- | --- | --- | --- | 
|  Validation Exception  |  400  |  No  |  Something is wrong with the required information - Eg. a malformed query.  | 
|  AccessDeniedException  |  403  |  No  |  User is not authorized to perform the requested operation.  | 
|  ResourceNotFoundException  |  404  |  No  |  Requested resource is not available.  | 
|  ThrottlingException  |  429  |  Yes  |  The server has received too many concurrent requests.  | 
|  InternalServerErrorException  |  500  |  Yes  |  The server failed to process the request for an unknown reason.  | 
|  UnprocessableException  |  422  |  No  |  Request cannot be processed due to known reasons - Eg. The query timed out.  | 
|  ConflictException  |  409  |  Yes  |  Concurrently running queries attempted to modify resources or data records concurrently and the conflict could not be resolved automatically. Please retry with an exponential back-off strategy.  |