[Bug]: Russell Theme renders block errors in the site editor on initial load

[jeyip]

Quick summary

When loading the Russell theme for the first time in the site editor, it renders with block errors.

Steps to reproduce

1. Apply branch to local calypso dev environment
2. Visit http://calypso.localhost:3000/new/beta
3. Enroll in the FSE beta
4. Pick a free test domain
5. Verify that Arbutus is a selectable theme
6. Create a site with Arbutus enabled and smoke test the theme

What you expected to happen

On initial load, there are no block errors

What actually happened

On initial load, there are block errors

Reproducibility

Consistent

Notes

Related to #58663

[creativecoder]

Potential fix at D71041-code.

Note that it's very possible this issue exists with other themes with starter content saved before Nov 28th, when D70425-code was deployed. cc @Automattic/theam

[creativecoder]

Resolved by D71041-code

[creativecoder]

Reopening, as there's another error showing for the Post Title block

TypeError: can't access property "rendered", h is undefined
    edit https://s0.wp.com/_static/??-eJylUe1uwyAMfKERL91X92Pas0CwIqcGMgz9ePu5mrJVmmhW7R/HnY8zB4fZDCkWjAVmriNFgbEqdJhHZTLCvt90910PrhJ7cJyGnWFy2eYTUPR47ALFbpI7uNVrEf3PBT0VI1Twtw/FgatHgUmgKpnlPN9SODvsXIpNXmEtxFfoNYegWa0JySNLS6M7z5ysh5CO1HT6Vi2HlnCSFDerLnq/avRRURuvpMGqNIP9yCTlYh1f/wxkDOemL4Gx0Wsce8J8+2ygMdvyt0eVu8StGTuTyah7SVMyMM0u2dz8va/m94SHpfj38NY/P7xstk/bx9fpE5ynTEM=:74
    Le https://s0.wp.com/wp-content/plugins/gutenberg-core/v12.0.1/vendor/react-dom.min.edd8b7a6.js?m=1624062436h:7
    Pj https://s0.wp.com/wp-content/plugins/gutenberg-core/v12.0.1/vendor/react-dom.min.edd8b7a6.js?m=1624062436h:10
    di https://s0.wp.com/wp-content/plugins/gutenberg-core/v12.0.1/vendor/react-dom.min.edd8b7a6.js?m=1624062436h:8
    Nj https://s0.wp.com/wp-content/plugins/gutenberg-core/v12.0.1/vendor/react-dom.min.edd8b7a6.js?m=1624062436h:8
    sc https://s0.wp.com/wp-content/plugins/gutenberg-core/v12.0.1/vendor/react-dom.min.edd8b7a6.js?m=1624062436h:8

[zaguiini]

Reopening, as there's another error showing for the Post Title block

That is fixed in the latest version of Gutenberg. I saw that and simply running trunk fixes the problem. Other themes suffer from the same issue if the page title is empty or undefined.

[creativecoder]

Thanks so much @zaguiini !

I've confirmed that when running Gutenberg trunk on the site I don't see the error... seems I can keep this closed after all.