The problem also is, I'm not really good with stuff like this. Have no clue to "backup a wallet" anyway.
All I usually do when installing a wallet on my PC is write down the seed phrase on paper. But in this particular case I forgot this.
Can you please read my previous post and answer on that?
I'm giving you an alternative to make sure you have a backup of the wallet or the seed itself before trying to fix stuff (like reinstalling Jaxx). Why won't you do that?
What exactly do you want me to answer to? I don't use Jaxx. I can't answer if the wallet will be lost if you update it to a new version, or if you can get any data from the dev tools options. I'm suggesting you something I can work it to try helping you.