#!/bin/bash
echo '12.05.2009 ERROR (User2) Problem (aa(bb)cc)dd with (ee) ff) Login' | \
sed -n "s/.*ERROR ([^)]*)/ERROR/p"
IyEvYmluL2Jhc2gKZWNobyAnMTIuMDUuMjAwOSBFUlJPUiAoVXNlcjIpIFByb2JsZW0gKGFhKGJiKWNjKWRkIHdpdGggKGVlKSBmZikgTG9naW4nIHwgXAogICAgc2VkIC1uICJzLy4qRVJST1IgKFteKV0qKS9FUlJPUi9wIg==