Upgrade went fine. The only issue is the website logo is now text. The logo is there in Protean settings but doesn't show up on website header. I deleted logo then re-uploaded it and still not there. This happened after upgrade.
I figured it out. After the upgrade, the logo was removed in the "Designer" app, not the "Protean" theme app. I was try to upload logo in "Protean". Once uploading logo again in "Designer" app, it now appears.
This is due to the style set reset which Anton mentioned. We added a ‘publish’ feature to styles builders in templates and the default style was reapplied to all sites. It should be enough just to set your old style as default again.