@FlourWeaver There was apparently an issue with the servers several days ago (not sure when, exactly, as I have been away for a few weeks), which caused issues with World states importing among other things. If you haven't tried since, you may want to try importing again before taking the drastic step of uninstalling and reinstalling the game (it's time consuming, and a lot to download, if you have any sort of download limit).
Also, rather than deleting your previous characters, you can simply move the save files or put them in a new folder within your save folder (assuming you're on PC). Means you can go back to them if you ever want to. Also, removing all your previous saves will mean you can't access the golden nug until you finish the game on a new character. 😉 Just a heads up.
If you have exported your world state from the Keep (using the same account as you use in the game), you're logged on in Origin and within Inquisition, you should be able to import that custom world state when you create a new character. Check that you don't have a firewall or anti malware program preventing Origin or the game from accessing the internet. Wonder where it's going wrong for you.