I went to copy a page in 7.4 and ran into some problems, I thought it's worth noting what happened, so hopefully we can get some better error messages.

1. I selected the page, right-clicked, chose "Copy"
2. Then I typed the new name in the field (it's not for the new name though, it's a search field that does the same thing as expanding the root node in the tree lower down).

3. Click the green Copy button and it looks like it's copying but if you check the inspector in Chrome, there is an angular error "TypeError: Cannot read property 'id' of undefined".

   Would be good to get an error here, something like "you need to choose the location to copy the new page to".

So yeah, my bad for not reading the field label, I just assumed the first thing it would want when copying is the new name, followed by the location.

By the way, I was happy with the root node, so never clicked it (I see now that it is selectable and turns into a tick when you click it). Not clicking that results in the same error.

When I click "Copy" again (to do it correctly) there does look like there's a red error message flashing up as it's loading, but it's too quick to read it, and I can't find what layer it's on. So there probably is an error there, just not showing properly for me.

By the way, I did have some caching issues when I upgraded to 7.4, lots of stuff didn't work until I opened up umbraco/assets/css/umbraco.css in it's own tab and refreshed it.