Me too and I have had this problem for the last 2 days....
I think I may have stumbled on to a fix:
This got my vault working correctly yesterday. It is still working fine this morning. Hope this works for you.
FYI...Also, click on "clear local cache" or "clear local data"
The first time I went there it said clear local "cache" when I went back it was clear local "data"
I have no clue why it did that...the "refresh vault" did not work, at least for me. I called support initially with the problem, very impressed with them btw, and the agent had me clear the "browser cache in Chrome" which fixed the launch problem...after couple days however, it started doing the same thing, nothing would launch from the vault. So, this time I searched the "community" and found your remark and stumbled on the fix 🤓
I would add to your fix steps...left click on the red LastPass extension box top right in the browser toolbar, then account, fix...👍
I've used LastPass for almost 5 years and this is the first issue I've ever had. Funny thing is, my mobile app was/is working just fine...I will also say, LastPass changed my life, stress
level, peace of mind and added several years to my life expectancy 🤣