Template parts loading... Site Editor impossibly slow

[bobbingwide]

[bobbingwide]

Well, I think this particular problem has gone away - template parts are now displayed differently

But I do have problems with the Site Editor hanging, with Gutenberg 13.1.0

It's painfully slow both in my SiteGround hosting - Chrome's now locked up on this screen capture -
and locally, where I get a WSOD; 12 errors in the Chrome console, starting with
edit.js:66 Uncaught TypeError: Cannot read properties of undefined (reading 'tinymce')
at edit.js:66:51
at Hm (react-dom.js?ver=5.9.3:1:214245)
at HTMLUnknownElement.g (react-dom.js?ver=5.9.3:1:47905)
at Object.An (react-dom.js?ver=5.9.3:1:48230)
at $n (react-dom.js?ver=5.9.3:1:49191)
at qm (react-dom.js?ver=5.9.3:1:214783)
at unstable_runWithPriority (react.js?ver=5.9.3:1:20757)
at ss (react-dom.js?ver=5.9.3:1:93777)
at jm (react-dom.js?ver=5.9.3:1:213973)

[bobbingwide]

30 seconds for a mouse move is a bit much!

[bobbingwide]

In my latest tests, in s.b/wp55 with WordPress 6.0, the Classic block is producing a slightly different version of the Uncaught TypeError: Cannot read properties of undefined (reading 'tinymce') message.

Uncaught TypeError: Cannot read properties of undefined (reading 'tinymce')
    at block-library.js?ver=016c65731f009ca1e5b5974727017d18:5514:29
    at invokePassiveEffectCreate (react-dom.js?ver=17.0.1:23517:22)
    at HTMLUnknownElement.callCallback (react-dom.js?ver=17.0.1:3942:16)
    at Object.invokeGuardedCallbackDev (react-dom.js?ver=17.0.1:3991:18)
    at invokeGuardedCallback (react-dom.js?ver=17.0.1:4053:33)
    at flushPassiveEffectsImpl (react-dom.js?ver=17.0.1:23604:11)
    at unstable_runWithPriority (react.js?ver=17.0.1:2764:14)
    at runWithPriority$1 (react-dom.js?ver=17.0.1:11306:12)
    at flushPassiveEffects (react-dom.js?ver=17.0.1:23477:16)
    at performSyncWorkOnRoot (react-dom.js?ver=17.0.1:22299:5)
react-dom.js?ver=17.0.1:20115 The above error occurred in the <ClassicEdit> component:

    at ClassicEdit (https://s.b/wp55/wp-includes/js/dist/block-library.js?ver=016c65731f009ca1e5b5974727017d18:5487:5)
    at Edit (https://s.b/wp55/wp-includes/js/dist/block-editor.js?ver=39c7981dd22ec80281080455892940e6:12918:5)
...

This problem is probably covered by WordPress/gutenberg#23086

The Classic block in question is the [bw_list] shortcode in the sequentially-biased.html template part.

<!-- wp:heading {"level":4}  -->
<h4>Sequentially Biased</h4>
<!-- /wp:heading -->

[bw_list post_type=bigram posts_per_page=16 orderby=date order=DESC exclude=0]

This particular instance could be reworked to use the shortcode block or even the query loop.

[bobbingwide]

The problem with the Classic block failing has now been resolved in Gutenberg 15.3.1 or WordPress 6.2-beta5.
See WordPress/gutenberg#48938

With the latest changes to the Site Editor the performance is also much better.

Closing therefore.