Hello, Are you able to download and open attachments on other browsers or is it exclusively Firefox? When you try to download or open the attachments does Firefox give you any error codes or responses. Many site issues can be caused by corrupt cookies or cache. In order to try to fix these problems, the first step is to clear both cookies and the cache. Note: ''This will temporarily log you out of all sites you're logged in to.'' To clear cache and cookies do the following: #('''Firefox 57 and above''') Click the Library button [[Image:57 library icon]] and choose History.<br>(Click the menu button [[Image:New Fx Menu]] and choose History in older Firefox versions.) #In the History menu, choose "Clear Recent History...". #Under "Time range to clear", select "Everything". #Now, click the arrow next to Details to toggle the Details list active. #From the details list, check ''Cache'' and ''Cookies'' and uncheck everything else. #Now click the "Clear Now" button. Further information can be found in the [[Delete browsing, search and download history on Firefox]] article. Did this fix your problems? Please report back to us!

Hi, Try to update the latest version of Gmail app. Also remove the caches and data in the gmail app. I hope this helps you. Thank you!!