When given an Embarcadero License Manager .slip file that points to an incorrect server host you will receive the below error message when trying to launch Delphi (in this case XE7):
[The license server reported the following error: The license server host was not found.]
After deleting the wrong .slip and importing a new .slip file with the correct host (via the License Manager Tool), at launch, Delphi XE7 still reported the above error.
It turns out that during the first import, RAD Studio made copies of the original .slip file in the folder C:\Program Files\Embarcadero\Studio\15.0\License\ and “Delete…” from their license tool did not work. After manually deleting the files from that folder and re-importing the correct .slip, Delphi XE7 now launches and property authenticates with the license server.