Check PHP before rebuilding the form. Contact Form 7 6.2 raised its minimum PHP requirement to 8.3. That gives you a specific compatibility check when a problem appears during an update. It does not mean every broken form has the same cause. 1
Identify which part failed
In WordPress, open Tools → Site Health → Info → Server and check the PHP version serving the website. A command-line PHP version can differ from the web server’s version. Also compare WordPress against the requirements of the Contact Form 7 version you intend to install. 23
For a site-wide critical error, record the time and corresponding server-log entry. For a form that keeps spinning while the page otherwise works, inspect the submission request in the browser’s Network panel. These symptoms belong to different stages of the request.
Recover without creating a second problem
Test a PHP or plugin change on a staging copy. Record the previously working version combination and confirm that a backup exists. Avoid changing PHP, the theme and several plugins together: a successful result would not tell you which change mattered.
After the fix, submit one clearly labelled test enquiry. Check both the form response and the receiving mailbox. A successful update notification is not an end-to-end form test.
Related reading
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