Open tabs are considered as history and if you use Clear Recent History to clear the history when you close Firefox then the open tabs won't reappear on the next start.
You will have to un-check that item and clear the history manually to make this work.

• Tools > Options > Privacy : History: [X] Clear history when Firefox closes > Settings
• https://support.mozilla.org/kb/Clear+Recent+History

i realize that that would work but then my history isnt cleared, im looking for a workaround. There really should be an option to not clear tabs. Also if you just clear history you dont lose tabs so why should it be different if your starting or restarting, it was like this before v3.5 afterall

You would have to set the pages as home pages and open the home pages on startup or open them by middle-clicking a bookmarks folder with those sites bookmarked.

• https://support.mozilla.org/kb/How+to+set+the+home+page

yeah thats not gona work, i have more 200 tabs in different groups at any given time and they are constantly changing

Then you will just have to restrain from clearing the browsing history automatically and do this yourself manually.

• Firefox > History > Clear Recent History
• Tools > Clear Recent History

• https://support.mozilla.org/kb/Clear+Recent+History

well i was partially able to fix the problem with session manager with restarting now saving a session, theres an option in session manager :) but that doesnt fix it losing days worth of changes to my tabs. this should so be an option. "clear browsing history but keep tabs"

There is no need to make another option as you suggested because there is already one in General > When Firefox starts that should be respected. In other words, if When Firefox starts is set to Show my windows and tabs from last time and Privacy > Settings... > Browser History is checked, then after restarting Firefox all tabs should be preserved.

Because of that, this should be marked as a bug.

If you want your history cleared and reopen the tabs then you have to clear the history yourself manually before closing Firefox.
There are a lot of background actions connected to clearing history items when you close Firefox.
Clearing the cache disables the disk cache altogether (see about:cache) and clearing the history will prevent tabs from getting reopened.
Cookies from tabs that are reopened are stored as part of the session data by default and are not removed.

But why there cannot be a simple way to automatically clear the history while keeping the tabs open (other than manually doing that or by automating a third-party software like BleachBit)? Exactly, what is the difference when Privacy > Settings... > Browser History is checked and Firefox is doing that automatically, and when I do that manually through Firefox > History > Clear Recent History...?

Firefox doesn't care if you clear the history manually, but if you set Firefox to clear personal data (history) when you close Firefox then this includes session data and that prevents tabs from getting saved and restored on the next start. That is how the Firefox developers see and have coded this and there is nothing to do about this.

I just sent a feedback at Firefox Input. Maybe we will be lucky and they create an option for this.

Good idea, its so basic and really seems like something that should be included (this is how it was before 3.5) and i cant think of a reason why not to include it. That aside session manager does a fairly good job of getting around this issue for me.

I don't know which regular expressions Firefox is using to validate such a text link, but it is very difficult to include every possible text link variation if they didn't use a very basic URL check.