Thanks for posting.
Error (100): File is missing indicates the script is unable to find the file being used for an import. Server side scripts are limited in their functionality, especially the import records script step. One limitation is a server side import script cannot import directly from another FileMaker Pro file. You would need to modify your script to have the data export to comma separated or another supported format. Please view this article at http://help.filemaker.com/app/answers/detail/a_id/7035 about the limitations on server side export and import scripts.
Another and often simpler alternative is to set up a "robot" file launched from an OS based scheduler that performs your import records script. This runs from the client side of the environment and thus avoids this limitation on imports.
A robot file typically is designed with settings in file options that open the file with an account/password that also opens the server hosted file with sufficient access permissions for the script on the hosted file to run and then also a specifies tha a small script in the robot file run automatically each time the robot file is opened.
That script is ususally just two steps:
Perform Script [//put reference to script on the server here]
The biggest thing to be careful about here is that should your script contain an error that results in an infinite loop, there were will no way to halt the looping script short of using the server console to close the file.