Normally, hitting enter in the qucikfix window leads to jump to the corresponding line. But when I hit enter, there is a message in the status line, says "xxx matchs, xx lines", instead of jumping. It seems that the enter key is mapped to strange key.
When I double click with mouse, it jumps normally. It suggests that the format of the line is correct. By the way, the quickfix window is opened by the command of vimgrep.
How can I find where the problem is?