The version of the FormsX.nsf currently being used on the Domino server should always be the version that shipped with the current Domino server. If users are using an older version iNotes mail template, the corresponding FormsX.nsf must also be present. For example, if using Domino 8.0.2 and some iNotes users have mail databases based on iNotes6.nsf, both the Forms8.nsf that shipped with Domino 8.0.2 and the Forms6.nsf from the same version of the iNotes6.ntf should be present on the Domino Server.Forms6.nsf is used to cache design elements for databases based off the iNotes6.ntf designs.