Uploaded complete error log. Issue is occurring when I click on "File View" option from Ambari.
You should try creating a new "FileView" instance that should resolve your issue. (delete the old fileview instance)
Ambari UI --> "admin" --> "Manage Ambari" --> "Views" --> "FILES" --> "Create Instance"
Additionally please make sure that you have the correct proxy users set already. Usually this indicates that your "Proxyuser" setting for the cluster is not correctly set.
So please double check if "proxyuser" in the "Services --> HDFS --> Configs".
Under the Advanced tab, navigate to the Custom core-site section. (Add property) is set correctly or not. In the following example we are assuming that ambari is running with "root" user so the following setting is as following:
In above case we a re assuming that you are running your ambari as "root" user hence the above setting.