Most likely file corruption. Save compacted copies, or use recover.
Run Recover, and see what the log says. Recover might fix this
Does the conversion log say anything ?
Are the older versions OK ? It might be interesting to see what pieces are missing
note: you may be able to delete these items before conversion
> Any idea how this happened ? Is it some weird artifact of file conversion ? Any ideas for remedying either problem ?
I can't comment on all areas, but can offer the following on the relationship with no field. Although you must select a field at each end of any relationship when it is created, if a cartesian relationship is defined and subsequently one or both of the fields is deleted the relationship will continue to function and graphically will appear as yours does, ie. attached to the top of the TO. That could explain what you are seeing now.
That sounds likely. This was an inherited system which started in FP3, and there's no telling what happened to it before I got my hands on it.
I deleted the TO which wasn't working and had no further problems with the file.
Two years later, a plausible idea surfaces. Thanks.