3.0.0 is a major update that came with complete code refactoring, therefore we recommend making a full backup or updating your theme on a staging environment before publishing to live.
After the update is done, save theme options settings to regenerate all assets, then clear your browser cache on front-end (Ctrl + Shift + R).
You might also run into issues if you installed a SSL certificate after installing WordPress. Best way to check this is with browser console and look for Mixed insecure content. To fix it, go to Settings - Reading and update both WordPress Address and Site Address to https.
If something goes bad after the update, use the rollback feature (Theme Options - Updates), to revert to a stable version.
