Usually when i can't save via plugin, i use mobile app.
You can try removing plug and re-adding it back, just to see and/or trying "save all entered data" on another website you have login details on..
If its ok with other sites, its just the website itself.. which is not uncommon.. In that case, the only way would be to add the site via mobile/use
Alternatively, go back to a previous version where it DID work.. or try beta version: https://support.google.com/websearch/an ... 7673?hl=en
eg may sites (increasing I've seen) break Lastpass, more often then they fix, because its easy enough to do different login/popup methods which requires an 'update' of Latpass..
Since the number of broken website always will exceed the fixes Lastpass does, it will always be a problem.
That's the negative side of doing what they do