when I post a new post, then click onto the button "upload a file" and select an image from my computer. But I actually do not click "Insert" or "OK", but instead switch to another browser-window which I have open. Then I go back to my Forum-website. Then I click onto the button "upload a file" again, but this button just stopped working. Clicking this button does not do anything anymore. In order to make this button working again, I need to refresh the page.