Confirmed! Steve1973's solution "resolved" the issue for me on the current version 4.94.0.
Unfortunately, this reduces one of the key security aspects of LastPass, but it's workable for now. Hopefully it will be resolved shortly in future versions so MFA can be re-enabled, but at least this is a temporary fix for me.
Same here. Maybe a little more accurate:
There seems to be a lot of the users responding to this thread indicating that the problem may be associated with 2FA.
I do not have 2FA enabled and have never enabled it, so 2FA may not be related to the problem.
Disable MFA and use another browser or the Mac OS Vault to kill local sessions, to force all the security aspects to reset. It seems MFA is causing some permissions conflicts with version 4.94 in Safari, that will be fixed in a (hopefully near-) future LastPass update.
Sure, disabling MFA makes LastPass a little less secure, but it's only temporary, and you can change your master password to something Uber-complex, and store it in Safari's passwords (again, its just temporary). If you do this, though, make sure your computer login is something adequately complex for where and how you use your computer, and that your iCloud/AppleID login is both adequately complex and has 2FA enabled.
I'm having this problem as well. I'm glad to know it's not just a local problem. But it's annoying as hell. No matter what I do, the Safari extension panel for LastPass appears empty. There is a badge on the toolbar icon (showing the number of matching sites), but that's it. Form fills and the Vault app work fine.
MacOS Monterey 12.0.1
MacBook Pro (16 inch, 2021) with M1 Pro CPU
Disabling 2FA did not help. Neither did disabling/re-enabling the Safari extension, removing/reinstalling the Mac app, rebooting, or clearing Safari cache.
Hmm, I fixed a part of the problem, maybe it works for you guys as well.
I don't know which of the actions fixed what, but now the problem with the empty window with a "-" in the title is gone. Also, autofill works again, and when I have multiple passwords for the same site, the little in-field button wit
h the password picker (e.g.  i.c.o. three passwords) works again.
I'm only left with the empty panel under "..." in the Safari extension itself.
Same problem here. Going to try disabling and re-enabling MFA. Completely disabling 2FA/MFA for an undetermined amount of time is not a viable workaround in my opinion.
macOS Monterey 12.3.1
Mac mini (M1, 2020)
👏🏻THAK YOU! YES! Confirmed but also have the Safari button working now. Here's my added input:
I'm ONLY seeing the blank Safari box if there aren't any passwords to fill in.
I want to note that it's outrageous that GoTo has left us hanging with NO suggestions, updates, or information on progress. This is embarrassingly terrible support and had me considering reversing the charge that I JUST paid. I held out hoping for some support. <OK...deep breathing exercises>