The editor has encounterd an unexpected error

We have the Conference Scheduler Pro plugin, and we used the import feature to populate all sessions and workshops for our summer conference. The information looks correct in the admin interface and the page with the shortcode, but every time we edit an event, we see the error: “The editor has encountered an unexpected error” with options to attempt recovery, copy post text, or copy the error.

I opened every workshop post and converted all of the default “Classic” blocks created from the import to the new Gutenberg blocks, but the error still appears.

The edits we make are saved correctly, but refreshing the workshops screen to clear that error every time we update a workshop is an impediment to our workflow. We’re on WordPress version 5.7.2.

Here’s what’s generated when I select “copy error.” The referenced scripts are all WordPress includes, not from other plugins that could be deactivated.

Ge@https://www.orbiscascade.org/wp-includes/js/dist/data.min.js?ver=943087ae96d075f126df689839bb96b9:2:30611
He/</<@https://www.orbiscascade.org/wp-includes/js/dist/data.min.js?ver=943087ae96d075f126df689839bb96b9:2:31373
we@https://www.orbiscascade.org/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:84:293
He@https://www.orbiscascade.org/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:97:464
zj@https://www.orbiscascade.org/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:228:406
Th@https://www.orbiscascade.org/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:152:225
tj@https://www.orbiscascade.org/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:152:152
Te@https://www.orbiscascade.org/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:146:151
Pg/<@https://www.orbiscascade.org/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:61:68
unstable_runWithPriority@https://www.orbiscascade.org/wp-includes/js/dist/vendor/react.min.js?ver=16.13.1:25:260
Da@https://www.orbiscascade.org/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:60:280
Pg@https://www.orbiscascade.org/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:61:16
ha@https://www.orbiscascade.org/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:60:451
Ja@https://www.orbiscascade.org/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:224:400
ch@https://www.orbiscascade.org/wp-includes/js/dist/vendor/react-dom.min.js?ver=16.13.1:93:81
e@https://www.orbiscascade.org/wp-includes/js/dist/data.min.js?ver=943087ae96d075f126df689839bb96b9:2:30992
t@https://www.orbiscascade.org/wp-includes/js/dist/data.min.js?ver=943087ae96d075f126df689839bb96b9:2:31063
instantiate/w</<@https://www.orbiscascade.org/wp-includes/js/dist/data.min.js?ver=943087ae96d075f126df689839bb96b9:2:22102
p@https://www.orbiscascade.org/wp-includes/js/dist/data.min.js?ver=943087ae96d075f126df689839bb96b9:2:11569
s/</</<@https://www.orbiscascade.org/wp-includes/js/dist/redux-routine.min.js?ver=284288e957394d2097c6fbe95625e2fb:2:9784
M/</<@https://www.orbiscascade.org/wp-includes/js/dist/data.min.js?ver=943087ae96d075f126df689839bb96b9:2:14845
U/</</<@https://www.orbiscascade.org/wp-includes/js/dist/data.min.js?ver=943087ae96d075f126df689839bb96b9:2:15272
dispatch@https://www.orbiscascade.org/wp-includes/js/dist/data.min.js?ver=943087ae96d075f126df689839bb96b9:2:13294
n@https://www.orbiscascade.org/wp-includes/js/dist/redux-routine.min.js?ver=284288e957394d2097c6fbe95625e2fb:2:9459
e/<@https://www.orbiscascade.org/wp-includes/js/dist/redux-routine.min.js?ver=284288e957394d2097c6fbe95625e2fb:2:5211
e@https://www.orbiscascade.org/wp-includes/js/dist/redux-routine.min.js?ver=284288e957394d2097c6fbe95625e2fb:2:5186
u/<@https://www.orbiscascade.org/wp-includes/js/dist/redux-routine.min.js?ver=284288e957394d2097c6fbe95625e2fb:2:5140

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