It looks like they fixed it, but if this happens in the future you can try what I did, which was to access the sub-pages of the Seller Hub using previously created bookmarks in your browser.
I was able to get into all of the sub-pages that I normally use, such as shipping, active listings, etc. The overview page was the page that kept crashing.
Of course, if you don't have any of these bookmarked, then... 😕
