group policy not working

Browse to the location in the message and see if you can find the file.  If it does not exist track down which group policy is missing. The long serial number is the unique identifier of the group policy. Review the policies in the group policy manager and find the one that ref that number.  Unlink it or remove and recreate.  If it is the default domain policy post back.  There is a method to recreate it but I can find the ref right now.  

There could be problems with the Sysvol  share.  If you can’t browse to sysvol post back.

Could be a dns issue.  The computer can’t find \\efftronics.local.  

Dfs service may not be running.

Name resolving working and also dfs service also running,could you sahare the  document or any commands to solving steps

Let’s rule out a missing gpt file.  

How many domain controllers do you have?

Can you browser to the sysvol folder?
Open file explorer and enter \\efftronics.local. Do you see sysvol?  
If so open sysvol then look for efftronics.local and then look for the folder that starts with {5ab1f29d- and ends with 562}
Do you see gpt .ini in the serialized folder?

If so and you have more than one domain controller repeat the same process above on each domain controller.
Open file explorer and enter \\domaincontrollername. Do you see sysvol?  
If so open sysvol then look for efftronics.local and then look for the folder that starts with {5ab1f29d- and ends with 562}
Do you see gpt .ini in the serialized folder?

Post back the results.

Run DCDIAG and REPADMIN
Save the results to a txt and post txt file. The output for those commands can be large at times.  

https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2008-R2-and-2008/cc731968(v=ws.10)

https://technet.microsoft.com/pt-pt/library/cc773062(v=ws.10).aspx

I keep the cmd window open.  After about 10 seconds another message apperas which says "Computer policy could not be updated successfully.  The following errors were encountered: The processing of Group Policy failed.  Windows attempted to read the file \\<FQDN>\sysvol\<FQDN>\Policies\{6AC1786C-016F-11D2-945F-00C04Fb984F9}\gpt.ini from a domain controller and was not successful.  Group Policy settings may not be applied until this event is resolved. This issue may be transient and could be caused by one or more of the following:

a) Name Resolution/Network Connectivity to the current domain controller.
b) File Replication Service Latency (a file created on another domain controller has not replicated to the current domain controller).
c) The Distributed File System (DFS) client has been disabled.