When you install DeMaSy, the setup install in the windows folder a file named Handle.exe.

This file is distributed by company SysInternals (www.sysinternals.com)

This file is used in relation with Documents module. At the beginning of DeMaSy, it was possible to detect when you closed a document opened by  DeMaSy. But because of technical changes due to Microsoft, the system cannot see now when you close a document. The handle.exe is the file that overcome this gap.