When the FileManager is defined using TagHelpers the defined schema is not serialized
The following FileManager definition:
<kendo-filemanager name="filemanager" upload-url="@Url.Action("FileManagerUpload", "FileManager")">
    <filemanager-datasource>
        <transport>
            <read url="@Url.Action("FileManagerRead", "FileManager")" type="POST" />
            <create url="@Url.Action("FileManagerCreate", "FileManager")" type="POST" />
            <destroy url="@Url.Action("FileManagerDestroy", "FileManager")" type="POST" />
            <update url="@Url.Action("FileManagerUpdate", "FileManager")" type="POST" />
        </transport>
        <schema>
            <filemanager-model id="path" has-children="hasDirectories">
                <fields>
                    <field name="path" type="string" from="Path"></field>
                    <field name="name" type="string" from="Name"></field>
                    <field name="extension" type="string" from="Extension"></field>
                    <field name="created" type="date" from="Created"></field>
                    <field name="createdUtc" type="date" from="CreatedUtc"></field>
                    <field name="modified" type="date" from="Modified"></field>
                    <field name="modifiedUtc" type="date" from="ModifiedUtc"></field>
                    <field name="size" type="number" from="Size"></field>
                </fields>
            </filemanager-model>
        </schema>
    </filemanager-datasource>
    <toolbar>
        <items>
            <item name="createFolder" />
            <item name="upload" />
            <item name="sortDirection" />
            <item name="sortField" />
            <item name="changeView" />
            <item name="spacer" />
            <item name="details" />
            <item name="search" />
        </items>
    </toolbar>
</kendo-filemanager>
generates the following script, without a schema definition:
<script> 
  kendo.syncReady(function() {
    jQuery("#filemanager").kendoFileManager({
        "uploadUrl": "/FileManager/FileManagerUpload",
        "toolbar": {
            "items": [{
                "name": "createFolder"
            }, {
                "name": "upload"
            }, {
                "name": "sortDirection"
            }, {
                "name": "sortField"
            }, {
                "name": "changeView"
            }, {
                "name": "spacer"
            }, {
                "name": "details"
            }, {
                "name": "search"
            }]
        },
        "dataSource": {
            "schema": {
                "model": {
                    "id": "path",
                    "hasChildren": "hasDirectories"
                }
            },
            "transport": {
                "destroy": {
                    "type": "POST",
                    "url": "/FileManager/FileManagerDestroy"
                },
                "read": {
                    "type": "POST",
                    "url": "/FileManager/FileManagerRead"
                },
                "update": {
                    "type": "POST",
                    "url": "/FileManager/FileManagerUpdate"
                },
                "create": {
                    "type": "POST",
                    "url": "/FileManager/FileManagerCreate"
                }
            }
        }
    });
}); 
</script>
The FileManager DataSource schema should be serialized