I was intrigued that I could copy from some parts of C::B but not others, so here's more information...
Copy from Logs windows: OK
Copy from debugger Call Stack: OK
Copy from Watch window: OK
Copy from About dialog: Welcome to Code::Blocks 12.11! (OK)
Copy from Scripting console: Welcome to the script console! (OK)
Copy from Call stack: OK
Copy from Disassembly (Mixed Mode on or off): No
Copy from code editor doesn't work for different file types and different perspectives.
When the paste doesn't work, nothing gets pasted. A clipboard viewer on the Window's side shows the contents go blank when copying from C::B editor.
Frankly, this is a low priority for me, but the info might be useful.