Smart Update Fails to Apply Patch: java.io.IOException: Unable to backup file

Smart Update Fails to Apply Patch: java.io.IOException: Unable to backup file

When attempting to install a patch using Smart Update (BSU), the “java.io.IOException: Unable to backup file” error occurs:

ERROR:

java.io.IOException: Unable to backup file <path>/weblogic_patch.jar to <path>/weblogic_patch.jar.bak
Verbose logging gives some more details:
java.util.concurrent.ExecutionException: com;bea.plateng.patch.PatchInstallationException: java.io.IOException: Unable to backup file <path>/weblogic_patch.jar

Cause:

This is a common problem customers experience when they try to apply patches while the WLS domain is running. Because the domain is running, the jar which Smart Update needs to write to is locked, and this error occurs.

Solution:

Please stop the WLS domain, and make sure there are no processes or services running which would be holding a lock on that jar file. If Node Manager is running, you should also stop that.
Once all those processes and/or services are stopped, please run Smart Update and apply the patch. It should work.