Message: Service geckodriver unexpectedly exited. Status code was: 0

Traceback (most recent call last):
  File "[..]/utils.py", line 283, in launch_browser
    client = webdriver.Firefox(firefox_options=options, log_path=log_path)
  File "[..]/.virtualenvs/user/lib/python3.6/site-packages/selenium/webdriver/firefox/webdriver.py", line 148, in __init__
    self.service.start()
  File "[..]/.virtualenvs/user/lib/python3.6/site-packages/selenium/webdriver/common/service.py", line 98, in start
    self.assert_process_still_running()
  File "[..]/.virtualenvs/user/lib/python3.6/site-packages/selenium/webdriver/common/service.py", line 111, in assert_process_still_running
    % (self.path, return_code)
selenium.common.exceptions.WebDriverException: Message: Service geckodriver unexpectedly exited. Status code was: 0

1518573330504   addons.xpi-utils    WARN    addMetadata: Add-on activity-stream@mozilla.org is invalid: [Exception... "Component returned failure code: 0x80520006 (NS_ERROR_FILE_TARGET_DOES_NOT_EXIST) [nsIFile.isFile]"  nsresult: "0x80520006 (NS_ERROR_FILE_TARGET_DOES_NOT_EXIST)"  location: "JS frame :: resource://gre/modules/addons/XPIInstall.jsm :: this.loadManifestFromFile :: line 971"  data: no] Stack trace: this.loadManifestFromFile()@resource://gre/modules/addons/XPIInstall.jsm:971 < syncLoadManifestFromFile()@resource://gre/modules/addons/XPIProvider.jsm:947 < addMetadata()@resource://gre/modules/addons/XPIProvider.jsm -> resource://gre/modules/addons/XPIProviderUtils.js:1231 < processFileChanges()@resource://gre/modules/addons/XPIProvider.jsm -> resource://gre/modules/addons/XPIProviderUtils.js:1578 < checkForChanges()@resource://gre/modules/addons/XPIProvider.jsm:3265 < startup()@resource://gre/modules/addons/XPIProvider.jsm:2182 < callProvider()@resource://gre/modules/AddonManager.jsm:263 < _startProvider()@resource://gre/modules/AddonManager.jsm:730 < startup()@resource://gre/modules/AddonManager.jsm:897 < startup()@resource://gre/modules/AddonManager.jsm:3081 < observe()@jar:file:///opt/firefox/omni.ja!/components/addonManager.js:65