Impossible to add a post thumbnail

[OhYS]

Hi,
I try to simply add a post thumbnail for a post by the dashboard, but when I click nothings happened or I have just a pop up windows without any choice on it… practically white one !!!
I have tried with Chrome, Safari and Firefox, but it’s always the same thing… I am just the only one to have this kind of problem ?
I think I don’t have any possibility to add this thumbnail via Cornerstone ?
Thank you for your answer

Yves

[jade]

Hi Yves,

You could try testing for a plugin conflict. You can do this by deactivating all third party plugins, and seeing if the problem remains. If it’s fixed, you’ll know a plugin caused the problem, and you can narrow down which one by reactivating them one at a time.

Let us know how it goes!