Could you try these steps to see if it fixes this issue?
If that doesn't work, could you try uninstalling the LastPass extension then redownloading it from here? https://lastpass.com/download/
I followed the steps and then re-installed just for good measure and this seems to have cleared the error. Thank you.
Just to close the loop on the issue I was having.
In my case, it started when one of my passwords needed to be updated. From that point on, I was having the can't contact the server error. I tried all of the suggested fixes, nothing worked.
I finally discovered that I could make a new password entry and it would save it and work. So I made a new copy of the offending password entry and then deleted the old one. It took another "clear local cache" to get everything working again, but in this case, that solved my issue.
"In my case, it started when one of my passwords needed to be updated. From that point on, I was having the can't contact the server error. "
This is what started the error messages for me as well. It didn't occur to me that it would have been relevant, but I did the same thing - create a new password entry, delete the one that couldn't be updated. For me, that alone did not fix. It does sound like if I had just cleared cached, that alone may have fixed it for me but I went and re-installed anyway.
Came here for the same thing. I tried the "solution" but it didn't work and the red banner just continues to show. Super annoying.