1. First check that:
- Your LastPass Icon is red (in Safari, the * will turn black instead of red)
- Your Preferences are enabled to autofill by going to the LastPass Icon > Preferences > General > make sure that "Automatically Fill Login Information" is enabled.
- The site is not 'Flash' or 'Silverlight' - LastPass doesn't support these sites. Right-click on the site's login fields and look at the context menu information to check
2. Still doesn't autofill? Re-save the site by deleting the entry and logging in as if for the first time.
3. Check that you didn't add the site as a 'Never URL'. Check in your LastPass Icon > My LastPass Vault > Settings > Never URLs.
4. If you still can't save or autofill, force-save the site with the Save All Entered Data feature.
5. If your site uses a multiple-page login, use the Save All Entered Data function on each page to save your information for each page separately.
6. If you still have trouble, submit a support ticket by clicking the link at the bottom.