I put the png-file in the system directory but there's still an error. If i manually replace it by opening the project in the rpg maker, i directly run into the next "file missing" error, plus all graphics in the open project are black, which means that you probably use a different RTP.

In germany we are using the so called "Common RTP" which can be downloaded at the frontpagebut since youre not using that many RTP graphics you can as well just import the ones you use.