Quality issues

Other Stock sites are irrelevant.  They have different acceptance criteria. 

You have quite a few lighting and focus problems.

Before contributring to Adobe Stock, ensure that your assets are visually & technically as good or better than current Stock inventory.  Submit only your best images, suitable for commercial use -- posters, product packaging, billboard ads, magazines, merchandise, etc...  Read these links.

• https://helpx.adobe.com/stock/contributor/help/reasons-for-content-rejection.html
• https://helpx.adobe.com/stock/contributor/help/quality-and-technical-issues.html
• https://helpx.adobe.com/stock/contributor/user-guide.html/stock/contributor/help/photography-illustrations.ug.html
• https://helpx.adobe.com/stock/how-to/tips-stock-image-acceptance.html
• https://helpx.adobe.com/stock/contributor/help/vector-requirements.html

Model/Property Releases:
https://helpx.adobe.com/stock/contributor/help/model-release.html
https://helpx.adobe.com/stock/contributor/help/property-release.html

Hi @Dieter Stahl ,

Goose on a stone is a bit underexposed.

Steinfigur: too much is out of focus.

Blume: Too much is not completely in focus and also you seem to apply vignetting. If you did you must not apply vignette to any of your files.

To help you figure out the issues with your files read all the information at tips to help you create better photos for Adobe Stock. Also, here are additional tip that will help you identify issue to correct. 

Best wishes

Jacquelin

Blume:

Das ist leicht unterbelichtet.

Preußische Schale:

Der Weißabgleich ist etwas »grün«, das Bild ist ganz leicht unterbelichtet und der Fokus liegt vorn auf dem Sockel, anstatt auf der Schale. Wenn man mit einer 1.8 Blende arbeitet, ist man rasch außerhalb des scharfen Bereiches.

in the last weeks I get a lot of refuses because of quality issues. All of the photos had been accepted on other stock sides.

By @Dieter Stahl

That's again a confirmation that other stock sites do a lesser job with detecting erroneous assets.

Steinfiguren christlich.jpeg - In addition to the focus issues, this one also has chromatic aberration among the tree branches 

Hello,

Focus - 

And focus

Brick wall - B&W - don't submit B&W

Focus

And focus

In a nutshell, you seem to have focus issues, and these issues are not quite good enough for Adobe Stock.

People who download these pictures will complain about the quality!

This is too many pictures to examine in detail. In future please post no more than 1-3 pictures for review.