With ACF Blocks in 5.5, "enqueue_assets" causes fatal error

[bronsonoquinn]

This is related to ACF Pro, but didn't happen until the upgrade to WP 5.5. I downgraded to 5.4.2 to make sure and I can verify it's a WordPress issue, likely related to REACT or the Rest API. I don't know enough about the Gutenberg editor to know if it's specific to that, so I'm posting here with "second-opinion" Workflow Keyword.

I have several custom blocks created using ACF Pro. One of them requires multiple javascript files and uses the "enqueue_assets" attribute to enqueue them.

When I try to edit any post, I get a popup error that covers the entire screen saying "The editor has encountered an unexpected error." and has 3 buttons: "Attempt Recovery", "Copy Post Text", "Copy Error". None of the buttons work.

In the console, I get these errors:

react-dom.min.js?ver=16.9.0:103 
TypeError: First argument must be a String, HTMLElement, HTMLCollection, or NodeList
    at t.exports (compose.min.js?ver=c4775e2aa9288586791e26a980eff851:9)
    at e.value (compose.min.js?ver=c4775e2aa9288586791e26a980eff851:9)
    at new e (compose.min.js?ver=c4775e2aa9288586791e26a980eff851:9)
    at compose.min.js?ver=c4775e2aa9288586791e26a980eff851:9
    at Vb (react-dom.min.js?ver=16.9.0:104)
    at Xi (react-dom.min.js?ver=16.9.0:151)
    at unstable_runWithPriority (react.min.js?ver=16.9.0:26)
    at Ma (react-dom.min.js?ver=16.9.0:52)
    at Yb (react-dom.min.js?ver=16.9.0:150)
    at O (react-dom.min.js?ver=16.9.0:120)

components-1480.js:24 
Uncaught TypeError: Cannot read property 'clientHeight' of null
    at G.hasOverflowedContent (components-1480.js:24)
    at G.fitTitle (components-1480.js:24)
    at components-1480.js:24

After the second error, the first error repeats and keeps getting hit every few milliseconds, telling me it has thousands of times within a minute.

I'll post this with ACF Pro, too, but wanted to mention here in case it's a WordPress bug. I don't know how many people use ACF blocks in the Block Editor, but it completely prevents people from editing posts if they have some.

Thanks!

[bronsonoquinn]

error screenshot

[SergeyBiryukov]

Hi there, welcome to WordPress Trac! Thanks for the report.

Have you heard back from ACF Pro yet? Were they able to track down the exact issue?