Personal Laptop details: Windows 8.1 64 bit Firefox version: 53.0.2 All the pop-ups which appear while using Firefox tends to slow down. On clicking download attachments in Gmail, the popup appearing to ask where to save the file, that window is too slow and at times doesnt work. Also, recently the 'drag and drop' feature to be used in Gmail doesnt work. Tried the following already: Uninstalled and Downloaded new firefox Cleared cache, cookies, history. Firefox profile logged out and logged in again.