Files installed in PreinstallFolder are deleted at the end of installation
Any files installed in PreinstallFolder (typically, the Target System\Temp\<SessionID> folder) are automatically deleted by the installer when the session ends. You should therefore only place temporary files in this folder, for example subinstallers, and not regular installation files.
To resolve this diagnostic, do one of the following.
|The file in question is intended as a temporary file||
Make sure that the file's installation attributes are set as follows:
|The file in question is a regular installation file||Move (drag & drop) the file to a different installation folder.|