Ok, so thats an interactive object. Thank you.
I want to replace the rollover function with an click funktion. So i click on a picture, another picture appears. I click a second time, it shows the picture before. That is all i want But it should work in the future for tablets with touch function.
I know it can work! See here in thos example, there i have no lock and i can resize the image that popups bei klicken on a shape below. There is no lock! But i dont understand what i do wrong. I activate the "'Use as button" und create a new cutom state.

I tried to explain, but you don't seem to understand. You are very new to Captivate? Probably using German version? Or another language anyway. If it is German, I understand even if you write in Goethe's language.
That example can even be a button. Itt has a Normal state which is empty (will probably be a shape with Alpha and stroke set to 0). What you show in the screenshot for the custom state has a RED border. The locked state in your first screenshot has a BLUE border, which is indicating the locked size of the original Normal state. Just add another image either with the Media button or by dragging from the Library: it will have a RED border and is completely unlocked.
Repeating if I understand your request well, which more like a flip card than a real rollover (for a real rollover the original image will remain and the extra image appears elsewhere):
- Select the custom state in the Object State panel.
- In the Properties panel for that image select Edit Image. You see the BLUE border.

- Set the Alpha to 0 to make that image invisible

- Close that dialog box. Back in the Object state panel, add the image you want to show when the image (button) is clicked. You'll see that it has a blue border and can be put anywhere. It has a RED border:

- Exit Object state. Add the command 'Go to Next State' to the image used as button.