I have an script with Selenium which was working on both pc and server correctly. A few days ago it stopped over server and still I have not figured out what is wrong. I set both of Firefox (41.0.2) and Selenium (2.53.5) similar over pc and local. 

By running:

```
from selenium import webdriver

browser = webdriver.Firefox()

```

With current version I face this error: 

```
selenium.common.exceptions.WebDriverException: Message: The browser appears to have exited before we could connect. If you specified a log_file in the FirefoxBinary constructor, check it for details.

```

I should mention that I run my code with setting DISPLAY:=1;

I decided to upgrade selenium to 3.0.2 and I faced the:

```
IOError: [Errno 13] Permission denied: 'geckodriver.log'

```

Based on recommendation of other people who faced this issue, I downloaded geckidriver and put it in /usr/local/bin. However, still I cannot run my code. Weird part is that the code run without any issue over pc!

Any advice or suggestions?

This is output of geckodriver.log:

```
(firefox:94561): GConf-WARNING **: Client failed to connect to the D-BUS  daemon:
/usr/bin/dbus-launch terminated abnormally without any error message
1484733755568   geckodriver     INFO    Listening on 127.0.0.1:35823
1484733756567   mozprofile::profile     INFO    Using profile path     /tmp/rust_mozprofile.UiIxs53qoUs1
1484733756568   geckodriver::marionette INFO    Starting browser /usr/bin/firefox
1484733756573   geckodriver::marionette INFO    Connecting to Marionette on localhost:44907

(process:95171): GLib-CRITICAL **: g_slice_set_config: assertion 'sys_page_size == 0' failed

```

Xlib: extension "RANDR" missing on display ":1".

```
(firefox:95171): GConf-WARNING **: Client failed to connect to the D-BUS daemon:
/usr/bin/dbus-launch terminated abnormally without any error message

(firefox:95171): GConf-WARNING **: Client failed to connect to the D-BUS daemon:
/usr/bin/dbus-launch terminated abnormally without any error message

(firefox:95171): GConf-WARNING **: Client failed to connect to the D-BUS daemon:
/usr/bin/dbus-launch terminated abnormally without any error message

  (firefox:95171): GConf-WARNING **: Client failed to connect to the  D-BUS daemon:
 /usr/bin/dbus-launch terminated abnormally without any error message

```

Thanks