If you are installing Dynamics AX 2012 Enterprise Search, you may find the following errors in the installation logs “Error executing code: No system global variables”. Depending on your SharePoint Farm configuration thefront-end servers can be configured with the BDC service running on both servers and cause the installer not to find the required DLLs in the global assembly cache (GAC).
To be able to install Enterprise Search under this type of configuration you will need to do the following steps:
You can manage the BDC service from SharePoint Central Administration -> System Settings-> Manage Servers in FARM and click on all the front ends. This information will be updated in the next version of the installation guides.