Save button is disabled

Hello Adobe,
I am using embeded pdf API to display pdf and allow to annotate document. I am saving annotations in my database and also able to load annotation from database to file. But now "Save" button is getting disabled. I am not able to download pdf file with modified changes.

I have attached screnshot for it. From "Download Pdf" option it's getting download file without any annotation But I want to allow to download file with annotation.
When I was testing with simple demo It's allow me to download file with annotation from save button. 
But now "Save" button is disabled so I am not able to download file with annotation.
After making any changes in file it's not getting enabled.

I have also attached following code.

var AdobePdfViewer = AdobePdfViewer || {};
AdobePdfViewer.AnnotationDataListName = 'AnnotationData';
AdobePdfViewer.ExistingAnnotationData = [];
AdobePdfViewer.ExistingAnnotationDataId = 0;
AdobePdfViewer.MeetingId = 0;
AdobePdfViewer.AgendaId = 0;
AdobePdfViewer.DocumentId = 0;

var pdfInfo = {
    username: _spPageContextInfo.userDisplayName,
    email: _spPageContextInfo.userEmail,
    url: "",
    x: 0,
    y: 0,
    id: 0,
    name: "",
    note: "",
    pege: 1,
    documentId: 0
};
var adobeDocViwer;
const saveOptions = {
    autoSaveFrequency: 0,
    enableFocusPolling: false,
    showSaveButton: true
};

document.addEventListener("adobe_dc_view_sdk.ready", function () {
    console.log("Adobe pdf viewer ready");
});

// document.addEventListener("adobe_dc_view_sdk.ready", function () {
AdobePdfViewer.OpenFileInPdfViewer = function (MeetingId, AgendaId, DocumentId, DocumentURL, DocumentName) {
    AdobePdfViewer.MeetingId = MeetingId;
    AdobePdfViewer.AgendaId = AgendaId;
    AdobePdfViewer.DocumentId = DocumentId;
    pdfInfo.name = DocumentName;
    pdfInfo.id = DocumentId;
    pdfInfo.documentId = DocumentId;
    pdfInfo.url = DocumentURL;
    AdobePdfViewer.GetAnnotationData(AgendaId, DocumentId);

    var adobeDCView = new AdobeDC.View({
        clientId: "e030789a44534e3394c88b51d63f39c2",
        divId: "adobe-dc-view"
    });
    var previewFilePromise = adobeDCView.previewFile({
        content: {
            location: {
                url: DocumentURL
            }
        },
        metaData: {
            fileName: pdfInfo.name,
            //id: "FileID1" //pdfInfo.id || "file1" /* this is required for annotation to work */
            id: "Document_" + pdfInfo.id
        },
    }, {
        showAnnotationTools: true,
        enableAnnotationAPIs: true,
        showDisabledSaveButton: true,
        //defaultViewMode: "FIT_PAGE",
        enableFormFilling: true
    });
    adobeDocViwer = adobeDCView;


    previewFilePromise.then(adobeViewer => {
        adobeViewer.getAnnotationManager().then(annotationManager => {
            window.AdobeAnnotationManager = annotationManager;
            // All annotation APIs can be invoked here
            console.log("loading annotations ....")

            return loadDocumentAnnotations(AdobePdfViewer.AgendaId, AdobePdfViewer.DocumentId).then(function (listOfAnnotations) {
                console.log("List of annotations from db1 ", listOfAnnotations);
                if (listOfAnnotations && listOfAnnotations.length) {
                    annotationManager.addAnnotations(listOfAnnotations).then(function () {
                        registerAnnotationEventListeners(annotationManager);
                    });
                } else {
                    registerAnnotationEventListeners(annotationManager);
                }
                document.title = pdfInfo.name;
                var div = document.querySelector("#righPanel");
                if (div) {
                    div.classList.remove("loading");
                }
                toggleRightPanel();

                var note = window.pdfInfo.note;
                if (note) {
                    annotationManager.selectAnnotation(note);
                }
            }).catch(function () {
                registerAnnotationEventListeners(annotationManager);
            });
        });

        adobeViewer.getAPIs().then(function (apis) {
            if (window.pdfInfo.page) {
                var x = Number(pdfInfo.x || 0);
                var y = Number(pdfInfo.y || 0);
                var page = Number(page) || 1;

                setTimeout(function () {
                    apis.gotoLocation(page, x, y);
                }, 800);
            }
            window.AdobeVieweApi = apis;
        });

        window.AdobeViewer = adobeViewer;
    });


    adobeDCView.registerCallback(AdobeDC.View.Enum.CallbackType.GET_USER_PROFILE_API, function () {
        return Promise.resolve({
            code: AdobeDC.View.Enum.ApiResponseCode.SUCCESS,
            data: {
                userProfile: {
                    name: window.pdfInfo.username,
                    firstName: "",
                    lastName: "",
                    email: window.pdfInfo.email
                }
            }
        });
    });

    adobeDCView.registerCallback(
        AdobeDC.View.Enum.CallbackType.SAVE_API,
        function (metaData, content, options) {
            console.log("Save button click call");
            return new Promise(function (resolve, reject) {
                var url = '/pdf/updatebinary?fileStreamId=' + pdfInfo.documentId;

                console.log("saving...")
                fetch(url, {
                    method: 'POST',
                    body: content
                }).then(function (response) {
                    return response.json();
                }).then(function (result) {
                    console.log("saving done");
                    resolve({
                        code: AdobeDC.View.Enum.ApiResponseCode.SUCCESS,
                        data: {
                            metaData: metaData
                        }
                    });
                }).catch(function (err) {
                    reject({
                        code: AdobeDC.View.Enum.ApiResponseCode.FAIL,
                        data: {
                            metaData: metaData
                        }
                    });
                });
            });
        }, {
            autoSaveFrequency: 0,
            enableFocusPolling: false,
            showSaveButton: true
        }
    );


    adobeDCView.registerCallback(
        AdobeDC.View.Enum.CallbackType.EVENT_LISTENER,
        function (event) {
            console.log("Alert annotation started.......................")
            console.log(event.type, event.data);
            toggleRightPanel('notes');
        }, {
            // Pass the events to receive.
            // If no event is passed in listenOn, then all the annotation events will be received.
            listenOn: [
                AdobeDC.View.Enum.AnnotationEvents.ANNOTATION_ADDED,
                AdobeDC.View.Enum.AnnotationEvents.ANNOTATION_CLICKED,
                AdobeDC.View.Enum.AnnotationEvents.ANNOTATION_MODE_STARTED
            ],
            enableAnnotationEvents: true
        }
    );

    adobeDCView.registerCallback(
        AdobeDC.View.Enum.CallbackType.EVENT_LISTENER,
        function (event) {
            console.log("preview selection end fired")
            AdobeVieweApi.getSelectedContent().then(function (result) {
                copyToClipboard(result);
            });
        }, {
            listenOn: [AdobeDC.View.Enum.FilePreviewEvents.PREVIEW_SELECTION_END],
            enableFilePreviewEvents: true
        }
    );


    adobeDCView.registerCallback(
        AdobeDC.View.Enum.CallbackType.EVENT_LISTENER,
        function (event) {
            console.log("event", event);
            var copiedText = event.data.copiedText;

            var frame = document.querySelector('#propIFrame');
            if (frame && frame.contentWindow) {
                var selectedField = frame.contentWindow.lastFocusedField;
                if (selectedField && /(input|select|textarea)/i.test(selectedField.nodeName)) {
                    selectedField.value = copiedText;
                }
            }
        }, {
            //Pass the PDF analytics events to receive.
            //If no event is passed in listenOn, then all PDF analytics events will be received.
            listenOn: [AdobeDC.View.Enum.PDFAnalyticsEvents.TEXT_COPY],
            enablePDFAnalytics: true
        }
    );

}
// });



function loadDocumentAnnotations(AgendaId, DocumentId) {
    return new Promise(function (resolve, reject) {
        var annotationData = [];
        if (AdobePdfViewer.ExistingAnnotationDataId > 0 && AdobePdfViewer.ExistingAnnotationData && AdobePdfViewer.ExistingAnnotationData.length > 0) {
            annotationData = AdobePdfViewer.ExistingAnnotationData;
        } else {
            annotationData = [];
            //return  JSON.parse(result.ResultString || [])
        }
        resolve(annotationData);
    });
    //return AdobePdfViewer.GetAnnotationData(AgendaId, DocumentId);
}

function registerAnnotationEventListeners(annotationManager) {

    var eventOptions = {
        // Pass the events to receive.
        // If no event is passed in listenOn, then all the annotation events will be received.
        listenOn: [
            "ANNOTATION_ADDED", "ANNOTATION_UPDATED", "ANNOTATION_DELETED"
        ]
    };
    annotationManager.registerEventListener(
        function (event) {
            console.log(event.type, event.data);
            annotationManager.getAnnotations().then(function (result) {
                console.log("all annotations => ", result);
                console.log("saving annotations");
                // saveDocumentAnnotations(pdfInfo.name, pdfInfo.url, result).then(function (done) {
                //     console.log("Annotations updated.")
                // });

                AdobePdfViewer.SaveAnnotationData(AdobePdfViewer.MeetingId, AdobePdfViewer.AgendaId, AdobePdfViewer.DocumentId, result, AdobePdfViewer.ExistingAnnotationDataId);
            });
        },
        eventOptions
    );
}

function toggleRightPanel(panel) {
    panel = panel || sessionStorage.getItem("rpanel") || "notes";
    document.body.setAttribute('data-rpanel', panel);
    sessionStorage.setItem("rpanel", panel);

    //AdobeViewer.executeCommand('TOGGLE_COMMENTING', true); 
    AdobeAnnotationManager.setConfig({
        showCommentsPanel: true
    });
}

function copyToClipboard(str) {
    var el = document.createElement('textarea');
    el.value = str;
    el.setAttribute('readonly', '');
    el.style.position = 'absolute';
    el.style.left = '-9999px';
    document.body.appendChild(el);
    var selected = document.getSelection().rangeCount > 0 ? document.getSelection().getRangeAt(0) : false;
    el.select();
    document.execCommand('copy');
    document.body.removeChild(el);
    if (selected) {
        document.getSelection().removeAllRanges();
        document.getSelection().addRange(selected);
    }
};

AdobePdfViewer.SaveAnnotationData = function (MeetingId, AgendaId, DocumentId, AnnotationData, ExistingAnnotationId) {
    // $(".preloader").fadeIn();    
    var objAnnotationData = {}
    objAnnotationData.MeetingId = MeetingId;
    objAnnotationData.AgendaId = AgendaId;
    objAnnotationData.DocumentId = DocumentId;
    objAnnotationData.AnnotationData = JSON.stringify(AnnotationData);

    var isAsync = true;
    var siteUrl = _spPageContextInfo.webAbsoluteUrl;
    if (ExistingAnnotationId > 0) {
        //console.log('update annotation');
        spRestAPICallsUtil.updateListItem(siteUrl, AdobePdfViewer.AnnotationDataListName, objAnnotationData, ExistingAnnotationId, isAsync)
            .done(function (data) {
                //console.log("Update Annotation SP", data);
                //DisplayNotification("Success", "Your annotation has been saved for this document!", "success");
                // $(".preloader").fadeOut(200);
            }).fail(function () {
                //DisplayNotification("Alert", "Error in saving annotation data. Please try again", "danger");
            });
    } else {
        // console.log('add annotation');
        spRestAPICallsUtil.createListItem(siteUrl, AdobePdfViewer.AnnotationDataListName, objAnnotationData, isAsync)
            .done(function (data) {
                //console.log("Save Annotation SP", data);
                AdobePdfViewer.ExistingAnnotationDataId = data.d.Id;
                //DisplayNotification("Success", "Your annotation has been saved for this document!", "success");
                //$(".preloader").fadeOut(200);
            });
    }
    return false;
}

AdobePdfViewer.GetAnnotationData = function (AgendaId, DocumentId) {
    var UserId = _spPageContextInfo.userId;
    var deferred = $.Deferred()
    var listName = AdobePdfViewer.AnnotationDataListName;
    var queryStr = "$select=*&$filter=(AuthorId eq " + UserId + " and AgendaId eq " + AgendaId + " and DocumentId eq " + DocumentId + ")";
    var siteUrl = _spPageContextInfo.webAbsoluteUrl
    // spRestAPICallsUtil.getListItemById(siteUrl, listName, queryStr, ptoID)
    spRestAPICallsUtil.getListItems(siteUrl, listName, queryStr, false)
        .done(function (data) {
            //console.log(data);
            if (data && data.value && data.value.length > 0) {
                var i;
                for (i = 0; i < data.value.length; ++i) {
                    // do something with `substr[i]`
                    AdobePdfViewer.ExistingAnnotationDataId = data.value[i].ID;
                    if (data.value[i].AnnotationData) {
                        AdobePdfViewer.ExistingAnnotationData = JSON.parse(data.value[i].AnnotationData);
                    } else {
                        AdobePdfViewer.ExistingAnnotationData = [];
                    }
                }

            }
            return deferred.resolve(data);
            //return deferred.resolve(JSON.parse(AdobePdfViewer.ExistingAnnotationData));
        })
    return deferred.promise();
}

function uuidv4() {
    return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function (c) {
        var r = Math.random() * 16 | 0,
            v = c == 'x' ? r : (r & 0x3 | 0x8);
        return v.toString(16);
    });
}