Meta Box

I confirm the error. The same form me. Exactly the same. However, inspecting the code of the referred file, it seems to be OK.

Can you guys check it out? Since I have several sites it seems the problem will start to cascade on all of them, since every metabox plugin is set to auto update!

Thank you!

EDIT: OH, just saw the last comma on the line #53!
Removing it fix the problem indeed.

Hej there!

Updating only the .JS solved my problems with the editor rendering in classic mode!
Thank you!

However, updating the .PHP file brings also to me — as reported by JC — the strange bug on VISUAL text input —— the ENTER KEY must be pressed twice to create a paragraph (or CTRL+ENTER twice for line breaks).

Always thank you, Ahn & Team!
G.

Update:

I tried including the WYSIWYG metabox in my theme using both ways, the regular method and with a IF/ELSE/$post_id condition (as mentioned above):

— Removed my custom snippet for blank <p>'s, it was not it the culprit, problem still there
— Emptied the cache, nothing
— When screen reloads, after saving, I see the visual editor on the VISUAL tab for a millisecond, then it disappears, like if it was a refresh applied on the element

So, tried to inspect the new WYSISYG.JS file you shared this morning and solved my problem by commenting/removing the following:

// Force re-render editors. Use setTimeOut to run after all other code. Bug occurs in WP 5.6.
$( function() {
    setTimeout( function() {
        $( '.rwmb-wysiwyg' ).each( transform );
    }, 0 );
} );

But of course, this is not a ideal solution.
I tried also changing the number param of the setTimeout function... Anything higher than 12, 13, solves the problem. Putting like 20 or even 999 works too.

But again, not ideal.
Oh my...
=(

IN TIME: No JS errors show up in the console.

Hello Ahn!

No, it is not working for me (although I have not tested on a clean default themed WordPress). Behavior:

If I open a post with already WYSIWYG content on it, the VISUAL tab do not load at all, just the CODE tab.

If I create a brand new post and add content, in VISUAL all is OK, I can write and yes, I can switch between CODE and VISUAL again. But in the moment I do save the post and screen reloads, the VISUAL is completely gone (I mean the textarea editor field too), but code is there.

On this very recent post, if I SHIFT+Refresh, the VISUAL field is back on track, however the content on it is rendered all in white color (can't see anything unless I select with mouse) and it is formatted in HTML, I can see the <p> tags, etc etc, exactly as the same on CODE tab.

Note: the meta-data IS saved correctly to the database.

But my theme situation could be interfering perhaps... I do register the metabox based on a IF/ELSE who looks what $POST_ID is being edited. It's something I needed to do in my theme for other reasons:

$post_id = null;
if ( isset( $_GET['post'] ) ) {
    $post_id = intval( $_GET['post'] );
} elseif ( isset( $_POST['post_ID'] ) ) {
    $post_id = intval( $_POST['post_ID'] );
}

if ($post_id == 111) {
    $meta_boxes[] = array(
        'id' => 'mb-for-post-111',
        (...)
    );  
} else {
    $meta_boxes[] = array(
        'id' => 'mb-for-other-posts',
        (...)
    );  
}

ALSO: I do erradicate anything related to GutenBerg on my themes. Using the plagued new editor is absolutely no option for me. I run this code to remove it:

// Begone, GutenBerg!
add_filter('use_block_editor_for_post_type', '__return_false', 10);
// Don't load GutenBerg-related stylesheets.
add_action( 'wp_enqueue_scripts', 'remove_block_css', 100 );
function remove_block_css() {
    wp_dequeue_style( 'wp-block-library' ); // WordPress core
    wp_dequeue_style( 'wp-block-library-theme' ); // WordPress core
    wp_dequeue_style( 'wc-block-style' ); // WooCommerce
    wp_dequeue_style( 'storefront-gutenberg-blocks' ); // Storefront theme
}

I will try in a matter of minutes your new JS including the metabox on a standard way (yet on my theme) and also on a regular clean WordPress install, with the default theme.

See you soon.
Thanks so far.