[TYPO3-english] has no rendering definition!

["HocomAdvies [  Wiechert Hooghwinkel]

Hi, 

In my first attempt creating a custom CE as explained in this article:  http://t3-developer.com/typo3-installation/typo3-anpassen/eigene-contentelemente-in-typo3-erstellen/
I’m experiencing some problems.  
I managed to install my created test extension and I can add the new CE from the plugins-tab into my page. Only the added CE has no possibilities to add an image or anything else? Also viewing the page in the FE i get: ERROR: Content Element type “my_extension_teaser” has no rendering definition!

So I am missing something, can’t figure out what and how. Any advise how to proceed? Thanks in advance.

Using Typo3 7.6.1

Regards,
HocomAdvies



Wiechert Hooghwinkel
www.hocom-advies.nl