Unable to open terminal >> how can i fixed it ?
CCR2004-16G-2S+
We need a better description of your problem. Is this via WinBox or WebFig or is this a serial terminal. Can you establish a WinBox or a WebFig session?
If you get a "Terminal - not permitted (9)" message box when trying to open Terminal, then your device has probably been hacked, see this thread: Device got hacked 1 min after connected to internet. If that's the case, then it's now time to Netinstall. After Netinstall, set a secure password and apply the default firewall configuration from MikroTik (which your CCR devices does not have): Buying - RB1100AHx4 Dude Edition - Questions about Firewall - #4 by rextended.
Provide configuration export
Ok, then it's not the same issue as the one in the thread I linked above. Did you try to use WinBox 4 to see if the problem also occurs there?
If that does not work, try to connect to the router with SSH. If that works you can run the export command that @rextended mentioned above. If SSH also has the same problem, then you'll need to add a script under System -> Scripts to be able to run the /export file=xyz command.