Diễn đàn hỗ trợ Firefox

I had a number of tabs open today (~40). Because Firefox started to malfunction, I had to restart Firefox. It happened to me before and I knew that I can restore my previous session so I safely closed the tabs.

When I restarted it, I opened a tab and then I tried to open the Application Menu, but accidentally closed the window. Now, when I've re-opened Firefox and attempted to restore the previous session only that last tab appeared.

Is it possible to recover the pre-previous session? I use Ubuntu 18.04. Where is this information located? and how can I retrieve it?

I attempted to install a router but Mozilla sent a caution message that the brand (Net Gear) was insecure. Which brands are secure routers?>I have a Mac Book Air purchased a few months ago and have never had internet at home. This is first attempt. Thanks.

After the last update, the PIP overlay button is different and larger because it contains the message "Watch in Picture in Picture" and when hovering the mouse on it makes it bigger because a second more detailed message appears below the first one.

I would like to make the PIP overlay button as small as it was before with no text at all. What do I have to do in order to obtain this effect?

I have two computers (say A and B). I want to move the entire Bookmark toolbar from A to a folder in the Bookmark toolbar on B. This would allow me to selectively move folders and bookmarks from the A Bookmark toolbar upload to the toolbar on B. So far I cannot get the Import or Restore to upload to a single empty folder on the B bookmark toolbar.

I have tried to upload previously exported Html and Json files from A to a specific empty folder on B's bookmark tool bar but either the file overwrites the entire toolbar on B or nothing appears to happen.

I thought that by selecting a folder in the "Manage Bookmark" dialog box that the subsequent upload of either the Html or Json files would all go there but it does not appear to work.

Any help would be appreciated.

Thanks.