After updating to 9.3.4, copying blocks to clipboard does not work anymore

Using Concrete / Help
1

I have upgraded a site from 5.7.3.1 to 9.3.4, of course with intermediate updates. It works pretty well, except some adjustments on my own code.

However, I cannot copy blocks to clipboard anymore ! It’s not related to custom code : I tried with a basic factory block (Html) and I have the same error.
Everytime I attempt to copy a block, I get a 404 error in the console :

jquery-3.7.1.min.js:2
POST /index.php/ccm/system/block/process/copy/256/References%2FDescription/1187 404 (Not Found)

Any idea on how to correct that ? Thanks !

2

That’s a weird one - are you able to view your clipboard at all? Sometimes there can be blocks in the clipboard itself erroring.

You might also check your logs in the dashboard to see what the actual PHP error is, if there is one.