How long the "copied" confirmation stays up.

The longest message shown as plain text, and so the longest one a user is expected to retype or quote by hand. **It cannot be set to separate "report this" from "fix your design", and does not try.** Measured over the messages that exist: the one-line design errors are 73 characters, the longest piece of pure user advice is 182 ("You can't connect two Net Labels with a wire..."), and the shortest message that asks to be reported is 188 ("...if you are seeing this please report it"). Six characters apart. Any threshold drawn between those two would be decided by a rewording, so the threshold goes well below both and some design errors get a Copy button they do not strictly need. That is the right way round. A user quoting a long error in a forum question wants to copy it whoever it is addressed to, and the cost of an extra button is a button; the cost of the other mistake is a bug report with the message retyped from memory, or missing.

How tall the block may get before it scrolls, so that a stack trace cannot push the rest of the error pane - the affected components, the Fix button - off the screen.