Upload image button not working [flash enabled]

Hello,

I upgraded to wordpress 3.5, with nextgen 1.9.5 and when clicking on the “upload images” button, nothing happens, if using the flash method.

When not using flash upload method, no problems.

Do you have some workarounds, rather than reverting to an older version of wordpress ?

Thanks.

http://wordpress.org/extend/plugins/nextgen-gallery/