Can publisher 4.2 open DTP files saved with versions 4.5 and 4.6?

[Smee]

No.

Publisher 4.6 (and 4.5) required significant amounts of changes in order to get them to be properly compatible with Vista. In addition to these changes the spelling engine was completely altered. For these reasons there is information encoded in the 4.5 and 4.6 DTP files which cannot possibly be understood by any version prior to these.

If you are migrating from 4.2 and are trialing a newer version we recommend you make a backup copy of all your DTP files before starting.

NB: All versions of publisher are backward-compatible (i.e. a newer version of the program can always open an older version's DTP file).