If you getting the below issue:
SecurityException: Failed to obtain user group information: org.apache.hadoop.security.authorize.AuthorizationException: User: hue is not allowed to impersonate

Resolution:
1. Open your core-site.xml inside /etc/hadoop and add the below properties entries

<property>
<name>hadoop.proxyuser.hue.hosts</name>
<value>*</value>
</property>
<property>
<name>hadoop.proxyuser.hue.groups</name>
<value>*</value>
</property>

2. Open the hdfs-site.xml inside /etc/hadoop and add the below property entry

<property>
<name>dfs.webhdfs.enabled</name>
<value>true</value>
</property>

3. Then restart both hadoop and Hue