GenerateBlocks Pattern Library Fails to Load with Gutenburg Plugin Enabled

Hey team,

I’m hitting an error where the Pattern Library (GenerateBlocks) refuses to load when the Gutenberg plugin is enabled. To be specific, if I go to “Edit Page > [GB] (Top Right) > Open Pattern Library”, the following happens: The pattern library model opens, I briefly see content layouts load in (but not the content), then I get a single error notification: “The editor has encountered an unexpected error.” [Copy Error].

Here’s the error:

SecurityError: Failed to read a named property 'document' from 'Window': Blocked a frame with origin "https://[REDACTED]" from accessing a cross-origin frame.
    at sl (https://[REDACTED]/wp-content/plugins/gutenberg/build/scripts/vendors/react-dom.min.js?ver=18.3.1:8:24289)
    at Gn (https://[REDACTED]/wp-content/plugins/gutenberg/build/scripts/vendors/react-dom.min.js?ver=18.3.1:8:42334)
    at https://[REDACTED]/wp-content/plugins/gutenberg/build/scripts/vendors/react-dom.min.js?ver=18.3.1:8:40630
    at Sl (https://[REDACTED]/wp-content/plugins/gutenberg/build/scripts/vendors/react-dom.min.js?ver=18.3.1:1:1741)
    at MessagePort.hl (https://[REDACTED]/wp-content/plugins/gutenberg/build/scripts/vendors/react-dom.min.js?ver=18.3.1:1:2131)

I’ve tried disabling and re-enabling GB and GB Pro, no luck. The error points towards the Gutenberg plugin, so I tried disabling that; lo and behold, everything went back to normal.

Any advice?