Magento 1.9.1 product save keeps loading

Hi, I have a problem with a Magento 1.9.1.0 site. When I try to edit a product, and save, it just keeps loading, but the product never saves: [login to view URL] Also the image upload buttons don't work. I don't receive any error. Also when looking in the log files, there is no note of any error. In the browser console I can see this: ----------------- [login to view URL] Uncaught TypeError: Cannot read property 'description' of undefined at [login to view URL] ([login to view URL]) at [login to view URL] ([login to view URL]) at [login to view URL] ([login to view URL]) at [login to view URL] ([login to view URL]) at new klass ([login to view URL]) at [login to view URL] ([login to view URL]) at new klass ([login to view URL]) at (index):1361 [login to view URL] @ [login to view URL] [login to view URL] @ [login to view URL] detectFlashVersion @ [login to view URL] initialize @ [login to view URL] klass @ [login to view URL] initialize @ [login to view URL] klass @ [login to view URL] (anonymous) @ (index):1361 (index):1379 Uncaught ReferenceError: id_7a1ed134c2fb98512b04875e578b3ac2_UploaderJsObject is not defined at (index):1379 ---------------------------- Everything worked well for months, until the site was moved to an other server with same PHP version (5.6, alt-php) I'm looking for someone who can solve this fairly quick (within the next hours). Thanks