Tested in chrome 54 and opera 41. When I click "Save" or "Save and stay" in the admin product page, the product might not be saved. To be exact:
- If I click on the diskette icon of the button, the page just reloads as if I just got in the product edit/add page without saving anything.
- If I click on the text of the button (e.g. "save"), the product is saved normally as it should.