There are a number of old torrents I carry from other users- not my current uploads.
Recently a few of those say 'File missing force check to override.'  I did that.  Also
tried to drag and drop the torrent file which has been on for years into the window.
That gives the duplicate message and asks to procede etc.

No change.  The media file shows it is full numerically-- nothing to download.

Shouldn't a drag and drop of the torrent file into Tixati remove the force check and start seeding?

Version on this is 2.73

A followup on this.  If I have current exported Tixati profile  and _then_ do a
restore, and Import that profile back in could I avoid this problem?

 I have a backup machine that mirrors all of my current Tixati, I may try that just to
test it.

No improvemtn on this.  I will make a new topic on Win7 Restore causes torrents
to break.

I am also having this issue, just updated to Tixati version 2.84 and "lost" a bunch of transfers that were on force recheck. I still have the torrent files, and if I open it in Tixati, it asks if I want to merge it into the existing transfer. I cannot see these transfers however.

I think that message says 'merge trackers'.  That is the message I've seen many times.
Using backup and restore in the Tixati menu can prevent meny problems.  But I don't recall the solution I made unless it was to copy everything over from a backup manually.  A good reminder to my profile backup right now.  ;-)