@pandaeyes ok i fixed it by using the crx file extractor http://crxextractor.com/. I needed to turn on the developer mode for this and do all manually but now i have all my old extensions

When i click on "add" it says "Install Chrome Extensions" but i already have it installed. It says i have to go to the extension manager and have to click on install so i press OK. After pressing OK i get directly navigate to the extension manager and the add-on i was trying to download didn't even appear.
Any solutions?

Note: In my download folder i have an extension file but the download is marked as canceled