problem is solved
It was my cache that was not deleted properly so it seems

Steven Speirs wrote:

What version of WP-SimpleViewer are you using?
I have just upgraded to WordPress 3.4 and have successfully been able to create and view a gallery created with the current version of WP-SimpleViewer (v2.3.0).

Please post the URL to your gallery so that I can take a look.

I use SV-v1 the advanced version of Versie: 1.5.4, because of my subdir /wp-content/photos/

I thought it was because I used ï instead of i in the name of the gallery but changing that was of no use (is where the gallery is) (is where the gallery should appear
and thanks again Steven for looking in to this

After upgrade WP to ver 3.4 I can't make new galleries
The gallerie itself is made but when placing the code op a page or post I get the message:" gallery not found"
older gallery's are published fine