Can not open file in Quickfix when Using CtrlP

[Rosin1]

When I pressed enter in the vimgrep quickfix window on a filename entry , the ctrlp search result window would pop up automatically even if I didn't call it and the file would not be opened. vim-Ack and Ag had the same situation. But when I disabled CtrlP plugin, vimgrep, vim-Ack and Ag worked properly. And I didn't find any option in CtrlP that can configure this behavior. Thanks!

[sheinz]

You might have mapped CtrlP to <C-m>. <C-m> is an alias for <CR> in the terminal.