I know that tere were smiliar questions, but non of the answer could solve my issue. 
I want to navigate from one page to another with btn click.
When i press a button there is an arror in the console:

```
Target-dbg.js:386 Uncaught (in promise) Error: Control with ID app could not be found - Target: TargetReportsView
at constructor._refuseInvalidTarget (Target-dbg.js:386)
at Target-dbg.js:262

```

Here is my routing manifest:

```
"routing": {
        "config": {
            "routerClass": "sap.m.routing.Router",
            "viewType": "XML",
            "async": true,
            "viewPath": "CompName.Emp_ITDB.Emp_ITDB.view",
            "controlAggregation": "pages",
            "controlId": "app",
            "clearControlAggregation": false
        },
        "routes": [{
            "name": "RouteMainView",
            "pattern": "RouteMainView",
            "target": ["TargetMainView"]
        }, {
            "name": "TargetReportsView",
            "pattern": "TargetReportsView",
            "greedy": false,
            "target": ["TargetReportsView"]
        }],
        "targets": {
            "TargetMainView": {
                "viewType": "XML",
                "transition": "slide",
                "clearControlAggregation": false,
                "viewId": "MainView",
                "viewName": "MainView"
            },
            "TargetReportsView": {
                "viewType": "XML",
                "viewName": "ReportsView",
                "viewId": "ReportsView"
            }
        }
    }

```

And my views:
 - Main

```
<mvc:View xmlns:core="sap.ui.core" xmlns:mvc="sap.ui.core.mvc" xmlns="sap.m" xmlns:html="http://www.w3.org/1999/xhtml" xmlns:smartFilterBar="sap.ui.comp.smartfilterbar" xmlns:smartTable="sap.ui.comp.smarttable" controllerName="CompName.Emp_ITDB.Emp_ITDB.controller.MainView">
<App>
    <pages><Page title="EmployeeDB">
        <content>

        <Toolbar width="100%" id="toolbar1" design="Transparent">

            <content>

                <Button xmlns="sap.m" text="{i18n>databaseBar}" id="databaseBarBtn"/>

                <Button xmlns="sap.m" text="{i18n>reportsBar}" id="reportsBarBtn" press="NavigateToReports"/>

                <Button xmlns="sap.m" text="{i18n>adminBar}" id="adminBarBtn"/>

            </content>

        </Toolbar>

        </content>
        </Page>
    </pages>
</App>

```

and - Reports

```
<mvc:View xmlns:core="sap.ui.core" xmlns:mvc="sap.ui.core.mvc" xmlns="sap.m"
controllerName="CompName.Emp_ITDB.Emp_ITDB.controller.ReportsView" xmlns:html="http://www.w3.org/1999/xhtml">
<App id="TargetReportsView">
    <pages>
        <Page title="Title">
            <content></content>
        </Page>
    </pages>
</App>

```

And last but not least my controloer:

```
sap.ui.define(["sap/ui/core/mvc/Controller"], function (Controller) {
"use strict";
return Controller.extend("CompName.Emp_ITDB.Emp_ITDB.controller.MainView", {
    /**
     * Called when a controller is instantiated and its View controls (if available) are already created.
     * Can be used to modify the View before it is displayed, to bind event handlers and do other one-time initialization.
     * @memberOf CompName.Emp_ITDB.Emp_ITDB.view.MainView
     */

    getRouter : function () {
        return sap.ui.core.UIComponent.getRouterFor(this);
    },

    onInit: function () {},
    /**
     *@memberOf CompName.Emp_ITDB.Emp_ITDB.controller.MainView
     */
    ClearSearchBtnPressed: function (oEvent) {
        this.byId("employeeSearchBar").setValue("");
    },
    /**
     *@memberOf CompName.Emp_ITDB.Emp_ITDB.controller.MainView
     */
    NavigateToReports: function (oEvent) {
        this.getOwnerComponent().getRouter().getTargets().display("TargetReportsView");
    }
});

```

});

I tried everthing that google was able to show me. 
I am really confused now. 
And I also tried delete "rootview" in "sap.ui5" - not working. 
Any help will be welcomed! Thanks in advance!