Blank page when editing custom post type

[elliotcondon]

Describe the bug
CPT edit screen is no longer working.
White screen (not of death).
ACF is completely broken.
You can no longer edit a field group.

To Reproduce
Steps to reproduce the behavior:

1. Install Gutenberg 4.5.
2. Install ACF (any version).
3. Navigate to the "Custom Fields > Add New" page .
4. Notice the lack of anything.

Expected behavior
ACF CPT should appear as expected with the classic editor edit page.

Screenshots

Additional context

• This was not an issue with Gutenberg version 4.4

[andremacola]

If you have the Classic Editor installed, you can use the dropdown menu and all works fine. But this is not the correct solution.

[pento]

Thank you for the bug report, @elliotcondon!

I can reproduce this same bug, it seems to be a regression caused by #12000.

[pento]

Ah, I see. It's because adding user_can_richedit() to the gutenberg_can_edit_post/gutenberg_can_edit_post_type filters will cause them to always return true if the current user has rich editing enabled. This will override the other checks that a CPT can work with the block editor.

I suspect that #12000 was the wrong approach here: rather than falling back to classic when rich editing is disabled, we should still load the block editor, but default to the code editor view, or perhaps a HTML block.

The fix for this should also include e2e tests confirming that CPTs that don't work in the block editor won't try to load it.

[thmarx]

I run into the same problem. Until it is fixed and released, I use this workaround:
add_filter('user_can_richedit', "disable_richedit", 10, 1);

public function disable_richedit($is_enabled) {
if (get_post_type() === "my_post_type") {
return false;
}
return $is_enabled;
}

[anantajitjg]

Same issue for me...I hope it will be fixed soon....

[merc28]

@thmarx I'm wondering if I should try this fix or try rolling back the 5.0.1 update.

I run into the same problem. Until it is fixed and released, I use this workaround:
add_filter('user_can_richedit', "disable_richedit", 10, 1);

public function disable_richedit($is_enabled) {
if (get_post_type() === "my_post_type") {
return false;
}
return $is_enabled;
}

[merc28]

I tried just deactivating my TinyMCE Advanced editor but it didn't help. So I assume this is a gantry 5 or an issue with my isotope rocket theme

[BramPeerlings]

Related; #12442

[merc28]

I found on the WordPress support forums that they have a quick fix: a script that restores the classic editor which then fixes this bug.

[alexnl]

I had this same issue. The following in register_post_type will fix the issue:
show_in_rest => false
This uses the classic editor for the post type as opposed to Gutenberg.
I realize this is not ideal and does not "fix" the issue. Commenting it here in case someone needs it working temporarily while the issue is debugged.