I highly recommend the following way for changing default app logo. Default logo is located at:
In order to change logo just create your logo in
That way you will override default logo without changing kernel. If after change logo is displayed the same, clean the cache.
We also have a dedicated extension related to these types of changes please refer to this article.
In new version it's also possible to change logo just by creating theme and uploading logo while editing it.
Developing application takes a lot of time. You can support application by donating. There is no company behind this application and it takes away my free time. Every donation matters and does not matter how small it is!