For the last few months I have had issues with records disappearing from a table I am creating in MapInfo v21 build.33. The polygons remain visible in the mapper window, but the record becomes a thick black line (resembling a deleted object) in the browser and I cannot access the data. If I close the workspace without saving then the records reappear when I reopen. However, recently I noticed that they are being populated with the information from other polygons (creating random duplicates).
Could anyone advise what is going on? And how I might protect the work I am doing from further corruption?
It sounds as if there is a broken link between the spatial and attribute data.
You can fix this by packing the table.
Unfortunately, there is a cost to this fix: Spatial objects with no link to the attribute will be removed from your table.
If you are able to select the spatial data from the map, you may be able to copy and paste it back into the table. Often users are not able to select these "ghost" spatial objects.
I can't tell what you have done wrong, or how to avoid it. Luckily, it happens very rarely.
Many years back, I created a tool that extracted objects from a table, saved these into a new temporary table, and deleted the records in the original table. Later the records from the temporary table were inserted back into the table again. Over time this worked fine, but at some point it got unstable. It turned out that packing the original table after deleting records made the table far more stable.