message: Fix potential error
diff: @@ -67,6 +67,7 @@ export default function NavigationBar({ provider, loadWeb3Modal, logoutOfWeb3Mod
  }, [roles, role, signedInAddress, cachedRoles]);
  function truncateAddress(addr) {
  + if (!addr) return addr;
  let prefix = addr.substring(0,6);
  let suffix = addr.substring(addr.length - 4);
  return prefix + "..." + suffix;
  