Did you clear the cache after the upgrade?
Are there any javascript errors on the page when you are in edit mode?
Are there any errors in the Dashboard → Reports → Logs?
There’s likely an error reported in the browser’s JavaScript console. Open it on the browser and then click on the edit button. Some error in JavaScript can block the other scripts from executing which can prevent you from editing your site.
Like Myq said it’s likely a javascript error, if you open your browser’s developer tools and click on the Console tab you should be able to see if there are any errors when you go into edit mode.
Dear @Myq and @hutman, thank you for your help, I really appreciate that.
I did what you asked and I have indeed some errors in my browser Console tab :
at HTMLSpanElement.<anonymous> (app.js?ccm_nocache=2454e9db72dcc5f307940dec547e5667862203ea:6:16170)
at HTMLSpanElement.c (events.js?ccm_nocache=2454e9db72dcc5f307940dec547e5667862203ea:1:900)
at HTMLSpanElement.dispatch (jquery.js?ccm_nocache=2454e9db72dcc5f307940dec547e5667862203ea:3:12444)
at r.handle (jquery.js?ccm_nocache=2454e9db72dcc5f307940dec547e5667862203ea:3:9173)
at Object.trigger (jquery.js?ccm_nocache=2454e9db72dcc5f307940dec547e5667862203ea:3:11573)
at HTMLSpanElement.<anonymous> (jquery.js?ccm_nocache=2454e9db72dcc5f307940dec547e5667862203ea:3:18991)
at Function.each (jquery.js?ccm_nocache=2454e9db72dcc5f307940dec547e5667862203ea:2:2881)
at n.fn.init.each (jquery.js?ccm_nocache=2454e9db72dcc5f307940dec547e5667862203ea:2:846)
at n.fn.init.trigger (jquery.js?ccm_nocache=2454e9db72dcc5f307940dec547e5667862203ea:3:18967)
at Object.publish (events.js?ccm_nocache=2454e9db72dcc5f307940dec547e5667862203ea:1:1487)
But this code is an unknown foreign language for me…
Any idea on how to fix the issue ?
As it may help : I use Elemental theme, no add-ons installed, and I have already clear the cache of both the site and my browser.
app.js?ccm_nocache=2…c547e5667862203ea:7 Uncaught TypeError: Cannot read properties of undefined (reading 'menu')
at HTMLSpanElement.<anonymous> (app.js?ccm_nocache=2…5667862203ea:7:9524)
at HTMLSpanElement.c (events.js?ccm_nocach…e5667862203ea:1:900)
at HTMLSpanElement.dispatch (jquery.js?ccm_nocach…667862203ea:3:12444)
at HTMLSpanElement.<anonymous> (jquery.js?ccm_nocach…5667862203ea:3:9173)
at Object.trigger (jquery.js?ccm_nocach…667862203ea:3:11573)
at HTMLSpanElement.<anonymous> (jquery.js?ccm_nocach…667862203ea:3:18991)
at Function.each (jquery.js?ccm_nocach…5667862203ea:2:2881)
at n.each (jquery.js?ccm_nocach…e5667862203ea:2:846)
at n.trigger (jquery.js?ccm_nocach…667862203ea:3:18967)
at Object.publish (events.js?ccm_nocach…5667862203ea:1:1487)
So after much trouble, and the precious help of @mnakalay, the website is now under 9.3.4
But I still have this bloody error which deters me from updating the website :
cms.js?ccm_nocache=3…3a47bfa3fb69284ba:1 Uncaught TypeError: Cannot read properties of undefined (reading 'menu')
at HTMLSpanElement.<anonymous> (cms.js?ccm_nocache=3…a3fb69284ba:1:13912)
at HTMLSpanElement.i (cms.js?ccm_nocache=3…a3fb69284ba:1:80876)
at HTMLSpanElement.dispatch (jquery.js?ccm_nocach…a3fb69284ba:2:40035)
at v.handle (jquery.js?ccm_nocach…a3fb69284ba:2:38006)
at Object.trigger (jquery.js?ccm_nocach…a3fb69284ba:2:70124)
at HTMLSpanElement.<anonymous> (jquery.js?ccm_nocach…a3fb69284ba:2:70726)
at Function.each (jquery.js?ccm_nocach…fa3fb69284ba:2:3129)
at ce.fn.init.each (jquery.js?ccm_nocach…fa3fb69284ba:2:1594)
at ce.fn.init.trigger (jquery.js?ccm_nocach…a3fb69284ba:2:70701)
at Object.publish (cms.js?ccm_nocache=3…a3fb69284ba:1:81471)