I recently clicked the button to encrypt all URLS in line with lastpass's suggestions. Since doing so, all the URLs are malformatted and as a result, no autofill feature works anymore. This, for me, breaks the product, and renders it as useful as a searchable password locked CSV file.
I am now looking at switching providers, since this is an unacceptable degredation in the service. Unfortunately, since the URLs are all broken, I cannot export them and use the export file to automatically create a vault anywhere else. This means I will need to go through and manually recreate all my logins with the correct URLs in whatever new product I choose.
So this is a warning to other users: TAKE A BACKUP OF YOUR VAULT BEFORE UNDERTAKING THE URL ENCRYPTION. It might just save you hours of time if you find that lastpass botches it, as they did for me and others.
Here is another thread raising the same issue, where advisers linked to a generic help article which didn't fix the issue. It was suggested this should be raised up in the company and the advisers stopped responding. Read into that as you please: https://support.lastpass.com/s/question/0D5TP00000KBCyP0AX/i-just-switched-to-the-new-encrypted-urls-per-the-prompt-in-my-addon-but-now-its-not-recognizing-websites-i-have-always-used-to-log-in-what-gives-this-is-untenable?language=en_US
Thanks lastpass! With this, plus the recent data breach, you have made it an easy decision to switch providers!