使用 ASN.1 到 C 编译器生成 .asn 文件的 C++ 兼容 C 源代码时出现意外的 TOK_WITH，需要 ';'

当我试图由ETSI通过命令"asn1c VAM-PDU-Descriptions.sean"生成与C++兼容的C源代码VAM-PDU-Descriptions.sean文件时，我得到了以下错误:

ASN.1 grammar parse error near VAM-PDU-Descriptions.asn:21 (token "WITH"): syntax error, unexpected TOK_WITH, expecting ';'
Cannot parse "VAM-PDU-Descriptions.asn"

我正在使用的.shans文件的前几行如下:

VAM-PDU-Descriptions {itu-t(0) identified-organization(4) etsi(0) itsDomain(5)
    wg1(1) 103300 vam(1) major-version-3(3) minor-version-1(1)}
DEFINITIONS AUTOMATIC TAGS ::=
BEGIN

    IMPORTS
    AccelerationChangeIndication, BasicContainer, CartesianAngle, ClusterBreakupInfo,
    ClusterJoinInfo, ClusterLeaveInfo, Curvature, CurvatureCalculationMode, 
    DeltaTimeQuarterSecond, GenerationDeltaTime, HeadingChangeIndication, ItsPduHeader, LanePosition, 
    LateralAcceleration, LongitudinalAcceleration, PathHistory, PathPredicted, 
    SequenceOfSafeDistanceIndication, SequenceOfTrajectoryInterceptionIndication, 
    SequenceOfTrajectoryInterceptionIndication, Speed, StabilityChangeIndication, StationId, 
    TrajectoryInterceptionIndication, VerticalAcceleration, VruClusterInformation, VruDeviceUsage, 
    VruEnvironment, VruExteriorLights, GeneralizedLanePosition, VruProfileAndSubprofile, VruMovementControl,  
    VruSizeClass, YawRate, Wgs84Angle
    FROM ETSI-ITS-CDD {itu-t (0) identified-organization (4) etsi (0) itsDomain (5) wg1 (1) 102894 cdd (2) major-version-3 (3) minor-version-1 (1) }
    WITH SUCCESSORS
    ;

    VAM ::= SEQUENCE {
        header ItsPduHeaderVam,
        vam    VruAwareness
    }

而且，据我所知，我得到了一个与上面代码的第21和22行相关的语法错误，不过我是直接从ETSI网站下载的.

有人能给我解释一下我错过了什么吗？