ErrorCode:
| "stale"
| "busy"
| "command"
| "invalid"
| "solve"
| "validation"
| "cancelled"
| "nothingToUndo"
| "nothingToRedo"
| "notActive"
| "load"
| "plugin"
| "file"
| "import"
| "protocol"
| "notFound"
| "superseded"
| "crashed"
| "disposed"
| "timeout"
| "init"
| "render"
Machine-readable error codes.