Cannot Add the Specified Assembly to the Global Assembly Cache

Symptoms

Installer for the Sharepoint feature fails with the error Cannot add the specified assembly to the global assembly cache: Atlassian.Confluence.SharePoint.dll.

Cause

The installer is having problems putting the assemblies in the GAC (Global Assembly Cache).

Resolution

  1. Start Confluence as both a local administrator on the machine and as an administrator within the SharePoint farm.
  2. Run setup_webparts.exe and setup_search.exe and choose uninstall for each. If it wants to install, just cancel for now as it thinks it is already uninstalled.
  3. Go to C:\Windows\Assembly and try to physically remove (right click -> uninstall) Atlassian.Confluence.SharePoint.dll and Atlassian.Confluence.SharePoint.Search.dll.
  4. Then run the install for setup_webparts.exe and then setup_search.exe.

This problem can also happen if the assemblies were already there and the installer couldn't remove them first or otherwise replace them.

If that fails, take a look at the /wiki/spaces/KB/pages/27687343 documentation.

There is no content with the specified labels