Content element inside Toolbar component doesn't work - css

Question

I'm trying to build a table with button on table's header. I'm guiding from here.
This is my code:
<core:View xmlns:core="sap.ui.core" xmlns:mvc="sap.ui.core.mvc"
xmlns="sap.m"
xmlns:l="sap.ui.layout"
xmlns:f="sap.ui.layout.form"
xmlns:t="sap.ui.table"
height="100%"
controllerName="xxxxx"
xmlns:html="http://www.w3.org/1999/xhtml">
<Page title="CONFIGURACIÓN DE LA CUENTA" navButtonPress="onCancel" showNavButton="true">
<content>
<f:SimpleForm id="form_requerimiento_datos_generales" minWidth="1024"
maxContainerCols="2" editable="true" layout="ResponsiveGridLayout"
labelSpanL="4" labelSpanM="4"
emptySpanL="0" emptySpanM="0" columnsL="2" columnsM="2"
validateFieldGroup="onValidateFieldGroup">
<f:content>
<core:Title text="Suscripciones"/>
<t:Table
rows="{/Subscriptions?$filter=UserSystem eq '1'}"
selectionMode="None"
visibleRowCount="7">
<t:toolbar>
<content>
<Title id="title" text="Listado de Suscripciones" />
<ToolbarSpacer/>
<Button
icon="sap-icon://add"
tooltip="Agregar Suscripciones"
press="addSuscription"/>
</content>
</t:toolbar>
<t:columns>
<!--columns-->
</t:columns>
</t:Table>
</f:content>
</f:SimpleForm>
</content>
</Page>
</core:View>
I have following error message:
Uncaught Error: failed to load 'sap/m/content.js' from https://sapui5.netweaver.ondemand.com/resources/sap/m/content.js: 0 - NetworkError: Failed to execute 'send' on 'XMLHttpRequest': Failed to load 'https://sapui5.netweaver.ondemand.com/resources/sap/m/content.js'.
I don't know why I get this error. I think that It's in this part of code:
<t:toolbar>
<content>
<Title id="title" text="Listado de Suscripciones" />
<ToolbarSpacer/>
<Button
icon="sap-icon://add"
tooltip="Agregar Suscripciones"
press="addSuscription"/>
</content>
</t:toolbar>
I don't know why content label is not accepted inside toolbar label (In example this works). When I take off content label of my page. I don't get error messages.
I would like to know what doing for to solve my problem.
Thanks for help me!
UPDATE 1
I solved already my problem but Now I have another problem. I have a problem with CSS of table header (This is overlapped with table body):

Answer 1

The label <t:toolbar> is the aggregation name and it expects a toolbar inside it.
So, ideally <t:toolbar> is followed by a sap.m.Toolbar control.
As to why it is throwing: sap/m/content error is because, it is expecting a control after the <t:toolbar>. Also, since your default namespace is sap.m so it looks for control ( in this case you have specified content) in the default namespace.There is no such control as sap.m.content. Thus, an error.
If you will check your guiding source, you will see they have an <m:Toolbar> after <toolbar> aggregation
Here is the updated code:
<t:toolbar>
<Toolbar>
<content>
<Title id="title" text="Listado de Suscripciones" />
<ToolbarSpacer/>
<Button
icon="sap-icon://add"
tooltip="Agregar Suscripciones"
press="addSuscription"/>
</content>
</Toolbar>
</t:toolbar>