404 index not found

Hello,

i have a web application that is work on wamp on windows server and its work fine, i moved the application folder to linux ubuntu 16.4 with apache.

i see the permission and apahe config.
when i try to open the application is't give me 404 page not found
under ci log the error is page not found index
i enable devlopment mode but no error found.
i change the log level to 4
the log file:
INFO - 2018-03-16 23:20:10 --> Config Class Initialized
INFO - 2018-03-16 23:20:10 --> Hooks Class Initialized
DEBUG - 2018-03-16 23:20:10 --> UTF-8 Support Enabled
INFO - 2018-03-16 23:20:10 --> Utf8 Class Initialized
INFO - 2018-03-16 23:20:10 --> URI Class Initialized
INFO - 2018-03-16 23:20:10 --> Router Class Initialized
INFO - 2018-03-16 23:20:10 --> Output Class Initialized
INFO - 2018-03-16 23:20:10 --> Security Class Initialized
DEBUG - 2018-03-16 23:20:10 --> Global POST, GET and COOKIE data sanitized
INFO - 2018-03-16 23:20:10 --> Input Class Initialized
INFO - 2018-03-16 23:20:10 --> Language Class Initialized
ERROR - 2018-03-16 23:20:10 --> 404 Page Not Found: /index
i tried to change database to wrong settings and its give me the same error with same log.

thanks.