Unexpected error 1249 when trying to get prices

@operator

I'm trying to get all the prices in a price level, for all inventory items

C# Code:

service.search(new PricingSearchBasic());

or:

            service.search(new PricingSearchBasic              {                  priceLevel = new SearchMultiSelectField                  {                      @operator = SearchMultiSelectFieldOperator.anyOf,                      operatorSpecified = true,                      searchValue = new []                          {                              new RecordRef { internalId = "1", type=RecordType.priceLevel }                          }                  }              });

The error in both cases is:

 {      "statusField": {          "statusDetailField": [              {                  "codeField": 1249,                  "messageField": "An unexpected error occurred. Error ID: icqp5ujpkihlqelvz85i",                  "typeField": 0              }          ],          "isSuccessField": false,          "isSuccessFieldSpecified": true      },      "totalRecordsField": 0,      "totalRecordsFieldSpecified": false,      "pageSizeField": 0,      "pageSizeFieldSpecified": false,      "totalPagesField": 0,      "totalPagesFieldSpecified": false,      "pageIndexField": 0,      "pageIndexFieldSpecified": false,      "searchIdField": null,      "recordListField": null,      "searchRowListField": null  } 

Any ideas?
Thanks!

Rodrigo.