'The license manager file... does not exist, or could not be opened' error when starting Maple

"'The license manager file... does not exist, or could not be opened" is a variation of the "Invalid or missing license file" errors. It indicates that Maple has not been activated, or that the license file itself is invalid or not properly placed. To remedy, you will need to either manually activate Maple, or ensure that a proper license file is in the correct location.