Unable to start server from console due to missing Domain Name entry

ISSUE :

Unable to start any Weblogic Managed server associated with domain (base_domain) from Console.

ERROR OBSERVED:

weblogic.nodemanager.common.ConfigException: The domain 'base_domain' at 'u01/app/middleware/user_projects/domains/base_domain' was not registered in the nodemanager.domains file . Please register the domain in the nodemanager.domains file.
at weblogic.nodemanager.server.NMServer.getDomainManager(NMServer.java:259)
at weblogic.nodemanager.server.Handler.handleDomain(Handler.java:227)
at weblogic.nodemanager.server.Handler.handleCommand(Handler.java:109)
at weblogic.nodemanager.server.Handler.run(Handler.java:71)
at java.lang.Thread.run(Unknown Source)

REASON:

Domain Name entry ( base_domain in our case ) entry was missing from nodemanager.domains file.

SOLUTION:

Step 1) Stop Node Manager Process by find PID and then kill it.

ps -ef | grep -v grep | grep -i weblogic.NodeManager
kill -9 <NM_PID>

Step 2) Take backup of nodemanager.domains file from below location:
$WL_HOME/common/nodemanager 
$cp nodemanager.domains nodemanager.domains_ORG

Step 3) Add domain name in nodemanager.domains file as below
“base_domain=u01/app/middleware/user_projects/domains/base_domain”
Save the file 

Step 4) Start Node manager
$WL_HOME/server/bin
$nohup ./startNodeManager.sh &