If you get an error message saying “The server was unable to create your template. Please notify your server administrator” when you try to save a reusable workflow as template, the reason could be that the name is too long.
When I ran into this I looked in the ULS log and found this:
SPSolutionExporter: System.IO.PathTooLongException: The specified path, file name, or both are too long. The fully qualified file name must be less than 260 characters, and the directory name must be less than 248 characters.
After renaming the workflow to a shorter name it worked (in my case only 10 characters worked). Looking at the ULS some more I found out that the original name I chose was still used in combination with the new name. So if you still want that long name for your workflow you could first create the workflow with a short name, publish it and then rename it to the long name. Now you can hopefully save it as a template.