$sfn(%s) failed with error %u: %s
The indicated expression refers to the folder from which the installer runs. Because installers are often run from temporary locations or from removable media such as CD-ROMs, the folder may disappear after installation is complete. As a result, your application might fail.
You should review the situation to determine if you really intend to refer to the Setup source folder. For example, this might be the case if you are installing shortcuts to a program that is located on a CD-ROM. If, on the other hand, you want to refer to a permanent folder, you should use a different folder alias.