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Right, I am slightly worried. I opened QGIS this morning to discover that part of the work I did yesterday was not there (the attributes where present in the table, but were not digitised anywhere on the interface). I had assumed that I had accidentally done something last night before I went home that caused this to happen.

So I thought, not to worry, it won't take long to re-digitise the lost polygons. I finished the work, produced the map and saved the project so that I could close QGIS and was very worried to see that of my 13 polygons, only four are left! This has happened simultaneously with two layers (the two layers show the same boundary but the polygons are subdivided in one of the layers).

Is there any way I can undo, this/fix this. Whilst I should have finished with the layer, it is not beyond the realms of possibility that I will be asked to make minor changes etc.

  • To be clear: are you saying you can see the attributes of the digitized polygons in the layer attribute table but can't see the geometry in the map window? If so what happens when you select a polygon in the attribute table and click 'zoom to selected' (I'm wondering if you have an issue with projections). – MappaGnosis Nov 20 '15 at 11:38
  • It seems that since I have had to do other things in my project the ghost polygons have also disappeared from the attributes table. Previously though, you could select them and 'zoom to selected' and the map window would end up in a completely different and blank area of the map. If you selected the layer and clicked 'zoom to layer' the map window took you to the visible polygons only. I'm not a particularly technical user of QGIS, but I didn't think you could change the CRS of some polygons and not others? – KMurkin Nov 20 '15 at 11:51
  • A CRS references a layer, not features inside a layer... Maybe share your shapefile so that we can test. – wiltomap Nov 20 '15 at 11:54
  • All your features in a given shapefile will have the same CRS. I suspect what is happening is that you are digitizing in one CRS (the project) but your shapefile has a different CRS, so you see the polygon on screen as you digitize (your ghosts) but when you save, the polygon is saved in the CRS of the layer (and 'disappears'). Make life easy for yourself and digitize in the same CRS as the Project. You can always reproject afterwards if necessary. – MappaGnosis Nov 20 '15 at 12:03
  • I have just checked and the CRS of the project and both the layers which I was working on are set to 27700 and I haven't actually used a different CRS either today or yesterday (I am aware of the issues when using the OpenLayers Plugin and always open that in a separate project rather than contaminate the main project). Could it be changed accidentally? – KMurkin Nov 20 '15 at 12:10

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