If you're trying to activate Maple, but get the message "There was an error while trying to write your license file", the activation program is having difficulty creating/modifying the license file due to a permissions limitation. There are a couple of possible workarounds:
Run the activation program manually with administrative rights. On Windows, you can right-click the program and select "Run as administrator". On Linux and Macintosh, you can run the activation script from the Terminal using sudo. For Macintosh users, you can also right-click/control-click the activation program, and select "Open" twice.
Perform an Offline Activation.