At a client, I was trying to add a solution and got this error in both PowerShell as Stsadm:
An object in the SharePoint administrative framework, “SPSolutionLanguagePack Name=0 Parent=SPSolution Name=yoursolution.wsp”, depends on other objects which do not exist. Ensure that all of the objects dependencies are created and retry this operation.
yoursolution.wsp: The Solution installation failed.
After googling a bit, I found this solution:
1. Stop the SharePoint Timer Service
2. Open C:\Application Data\Microsoft\SharePoint\Config\<<GUID>> folder
3. Take a backup of Cache.ini file
4. Delete all the XML files in the GUID folder
5. Open the Cache.ini file in edit mode and delete the contents of it.
6. Type 1.
7. Save and close the file.
8. Start the SharePoint Timer Service.
It did the trick, although I cannot really recommend deleting and modifying SP internal documents. After you restart the Timer Service, SP creates all those xml files again.