Document type is missing after generating Document Services

Hello all,

I generated a document service based on my query "axdExportCustomer" with several tables.

My service class "ExportCustomerService" is full of compilation errors, because a document type ExportCustomer is missing:

/// <summary>
///    The <c>ExportCustomerService</c> class serves as the document service for the <c>ExportCustomer</c> document type.
/// </summary>
class ExportCustomerService extends AifDocumentService
{

}

For example in the read() method of the service class:

/// <summary>
///    Finds data objects.
/// </summary>
/// <param name="_queryCriteria">
///    The query criteria to use to find the data objects.
/// </param>
/// <returns>
///    A <c>ExportCustomer</c> document that contains the specified data objects.
/// </returns>
[AifDocumentFindAttribute, SysEntryPointAttribute(true)]
public ExportCustomer find(AifQueryCriteria _queryCriteria)
{
    ExportCustomer exportCustomer = new ExportCustomer();
    this.findList(_queryCriteria, exportCustomer );
    return exportCustomer ;
}

Almost all the methods reference this variable "ExportCustomer", throw the error "Syntax error" or "Variable ExportCustomer is not declared".

How do I create this document type?