When I try to click on the link you originally posted, I am redirected to the issue TOC. That suggests that maybe a gallery is missing, or there is a difference between published article settings. When you click the link, have a shell window open and tail the Apache error log and see what happens.
Thank you for your help. I have checked the article settings, nothing found. I also don’t have access to the logs, so that doesn’t work unfortunately.
But I solved the problem with submitting the same article again (using quick submit plugin). Since the article DOI has to be the same I manually in the DB changed the DOI of original article to something totally strange and copied the correct DOI to the new article. After exporting the DOI once more to the CrossRef everything looks OK now.