You can try the steps in this article [[Downloads window is blank]]

Thanks, I tried it but it does not solve the problem. The download window remains empty.

Here are some things to look at: It's possible that Firefox is set to forget your download history. [https://support.mozilla.com/en-US/kb/Clear%20Recent%20History#w_how-do-i-make-firefox-clear-my-history-automatically This article] explains how to make Firefox forget your history so If you do the opposite it could fix things. In this case it would be to make sure those history settings are set to '''Remember History'''. If that was already set to remember history or it doesn't work, you can try starting in [[Safe Mode]]. When the safe mode window comes up, check '''Reset toolbars and controls''' and '''Reset all user preferences to Firefox defaults''' and then click the '''Make changes and restart''' button. If that doesn't work, try [https://support.mozilla.com/en-US/kb/Basic%20Troubleshooting#w_8-make-a-new-profile these instructions for making a new profile]. If using Firefox with a new profile works, you'll probably want to copy over some settings (bookmarks, passwords, etc.) from your old profile. Those instructions are in [[Recovering important data from an old profile]].