Why do I get a General Server Failure error in SecureFX?

When transferring files to an Athena locker using SecureFX, what does the following error message mean?

(File) could not be opened by the server.

General Server Failure

(File) will not be transfered.

Context

Windows
Secure FX

Solution

This error message is most likely result of the Athena locker being over its quota. Instructions on checking quota can be found at [archive:How to Find Your Quota]. Or you can use the following Athena command:

add consult; afsquota lockername