title: Cassandra do not launch: encountered during startup: Expecting URI in variable: [cassandra.config]. Found[cassandra.yaml]
body: <p>I was using Cassandra normally last day, but after installing maven and restarting my computer, I am getting this error message when I launch CQLSH:</p>
  
  <pre><code>Connection error: ('Unable to connect to any servers', {'127.0.0.1': error(111, "Tried connecting to [('127.0.0.1', 9042)]. Last error: Connection refused")})
  </code></pre>
  
  <p>And when launching this command line:</p>
  
  <pre><code>sudo cassandra -R
  </code></pre>
  
  <p>I have this error message:</p>
  
  <pre><code>Exception (org.apache.cassandra.exceptions.ConfigurationException) encountered during startup: Expecting URI in variable: [cassandra.config]. Found[cassandra.yaml]. Please prefix the file with [file:///] for local files and [file://&lt;server&gt;/] for remote files. If you are executing this from an external tool, it needs to set Config.setClientMode(true) to avoid loading configuration.
  org.apache.cassandra.exceptions.ConfigurationException: Expecting URI in variable: [cassandra.config]. Found[cassandra.yaml]. Please prefix the file with [file:///] for local files and [file://&lt;server&gt;/] for remote files. If you are executing this from an external tool, it needs to set Config.setClientMode(true) to avoid loading configuration.
      at org.apache.cassandra.config.YamlConfigurationLoader.getStorageConfigURL(YamlConfigurationLoader.java:80)
      at org.apache.cassandra.config.YamlConfigurationLoader.loadConfig(YamlConfigurationLoader.java:100)
      at org.apache.cassandra.config.DatabaseDescriptor.loadConfig(DatabaseDescriptor.java:268)
      at org.apache.cassandra.config.DatabaseDescriptor.daemonInitialization(DatabaseDescriptor.java:147)
      at org.apache.cassandra.config.DatabaseDescriptor.daemonInitialization(DatabaseDescriptor.java:132)
      at org.apache.cassandra.service.CassandraDaemon.applyConfig(CassandraDaemon.java:665)
      at org.apache.cassandra.service.CassandraDaemon.activate(CassandraDaemon.java:609)
      at org.apache.cassandra.service.CassandraDaemon.main(CassandraDaemon.java:732)
  22:28:18.449 [main] ERROR o.a.c.service.CassandraDaemon - Exception encountered during startup
  org.apache.cassandra.exceptions.ConfigurationException: Expecting URI in variable: [cassandra.config]. Found[cassandra.yaml]. Please prefix the file with [file:///] for local files and [file://&lt;server&gt;/] for remote files. If you are executing this from an external tool, it needs to set Config.setClientMode(true) to avoid loading configuration.
      at org.apache.cassandra.config.YamlConfigurationLoader.getStorageConfigURL(YamlConfigurationLoader.java:80) ~[apache-cassandra-3.11.4.jar:3.11.4]
      at org.apache.cassandra.config.YamlConfigurationLoader.loadConfig(YamlConfigurationLoader.java:100) ~[apache-cassandra-3.11.4.jar:3.11.4]
      at org.apache.cassandra.config.DatabaseDescriptor.loadConfig(DatabaseDescriptor.java:268) ~[apache-cassandra-3.11.4.jar:3.11.4]
      at org.apache.cassandra.config.DatabaseDescriptor.daemonInitialization(DatabaseDescriptor.java:147) ~[apache-cassandra-3.11.4.jar:3.11.4]
      at org.apache.cassandra.config.DatabaseDescriptor.daemonInitialization(DatabaseDescriptor.java:132) ~[apache-cassandra-3.11.4.jar:3.11.4]
      at org.apache.cassandra.service.CassandraDaemon.applyConfig(CassandraDaemon.java:665) [apache-cassandra-3.11.4.jar:3.11.4]
      at org.apache.cassandra.service.CassandraDaemon.activate(CassandraDaemon.java:609) [apache-cassandra-3.11.4.jar:3.11.4]
      at org.apache.cassandra.service.CassandraDaemon.main(CassandraDaemon.java:732) [apache-cassandra-3.11.4.jar:3.11.4]
  </code></pre>
  
  <p>What is wrong with Cassandra please ?</p>
  
  <p>I even uninstalled it and reinstall again without success.</p>
  
  <p>I suspect that Maven installed another Java version or something ... hope you can help on this case.</p>
  
  <pre><code>Cassandra Version: 3.11.4
  
  Java version:
  
  openjdk version "1.8.0_222"
  OpenJDK Runtime Environment (build 1.8.0_222-8u222-b10-1ubuntu1~16.04.1-b10)
  OpenJDK 64-Bit Server VM (build 25.222-b10, mixed mode)
  
  OS:
  Ubuntu 16.04
  
  </code></pre>