Thi s post offers a solution to the very non-descriptive SharePoint error message “Cannot uninstall the LanguagePack 0 because it is not deployed”, which might appear while trying to update a wsp solution.
Assume you’re trying to install, update or uninstall a SharePoint solution (.wsp package) using PowerShell-commands Install-SPSolution, Update-SPSolution or Uninstall-SPSolution (respectively). Operation fails with the following (or similar) error:
Error: Cannot uninstall the LanguagePack 0 because it is not deployed
I have actually seen this also in the form of “Cannot uninstall Language Pack 0 because it is not deployed”, but I think the other form of the error is the one that pops up in the PowerShell.
In Central Admin the solution is in Error state.
You can find quite a lot of solutions online, but they weren’t really working for me. I tried restarting services, removing the package and meddling with the dll-files, but to no avail. However, the actual “last operation details” on the CA page hinted that the problem was in fact in one of the features. The feature in question included some content types, and toying around with them is like playing baseball with hand grenades, so you have to tread carefully in cases like these.