Cannot uninstall Language Pack 0 because it is not
deployed when attempting to uninstall solution on SharePoint 2010 
Issue: Cannot uninstall Language Pack 0 because it is not
deployed
Solution: Follow the below steps to resolve
the issue.
1.    Ensure to check the
solution store(Central Administration-->System Settings--> Manage farm
solutions) and saw that the solution I was updating was not deployed and thrown
error. The error it gave was not able to do GAC deployment of the dll. So I
went to GAC and uninstall the WSPs related dlls  and deployed the wsps again
from central admin.
2.   
From
services.msc I stopped and restarted the SharePoint 2010 Timer service and the
SharePoint 2010 Administration service.
3.   
Then I ran
the power shell command again. this time the WSP got updated.