We have a simple digital signage solution which uses container fields to deliver content via FileMaker Server to client PCs on the network. A local FileMaker file contains a script which gets the playlist from the server, and then uses a local layout to display the slides requested by the playlist from the server. This solution runs on Windows PCs, and is administered by users via Windows, as well.
Containers containing wmf files appear to be converted by the player application into PNG files, and stored in the windows user's "AppData/Local/Temp" directory as "FMTEMPFM####_#" files. Unlike other files placed in temporary storage, these converted .png files appear to not be deleted automatically by FileMaker on a clean client exit. Because they are downloaded and converted every time the container is called, the directory fills up over time, and eventually causes the C: drive on the PC running the player application to fill up and stop the application from functioning.
This problem does not appear to happen with PNG or JPEG files placed in the containers. We have not tested with PDF files.
This solution is running on Windows PCs. We have seen this issue on every version of FileMaker since 12. We are running Professional as the client in all cases, because we own a site license.
Please let me know if you need additional information. This solution does not contain proprietary information, so I would be happy to include copies of both the server and client files.