I'm hoping someone out there might be able to help or suggest some tests to try and resolve some very odd QGIS behaviour of late…
Our core GIS team of 4 users has been testing v2.10 prior to roll-out for the remainder of the organization.
In the past couple of weeks we have had some very odd shapefile corruption things happening and are yet to isolate or identify a potential cause…
These have included:
- Editing one line (using the scissor tool to split into two records) and having the resulting records attributes completely replaced by attributes from another geometry no-where near the edited row (spatially or in the attribute dbf)
- Line geometries completely disappear while their attributes get associated with an unrelated geometry
- Line geometry get partially deleted and replaced with a vertice in infinity (line visually extends beyond the dataset and no matter how far zoomed out you never see the end)
The above is happening in a polyline layer, that we did discover has some multi-line geometries..? Perhaps this is impacting… but never saw this issue with v2.8 and the same layer.
The layer has undergone MANY save-as's in the past week and many verify geometry checks as we thought invalid geometry may have been the cause…
In another separate layer yesterday, to a separate user (me) i created a layer with approx 30 polygons… adding, deleting some and doing some 'avoid intersection' to remove overlaps. Layer looks fine in qgis, saved and also a save-as to a completely new file but when i load into ArcGIS online (and later is ArcMap as a test) some of the overlaps and deleted objects are still there. Close and reopen qgis, reopen the file and they are definitely not.
The project was created in v2.8 that i was editing in (but had been saved in 2.10).
Does anyone have any ideas/suggestions.
We do still have 2.8 installed as well as 2.10? We have never encountered issues like this when testing other new qgis versions while still running old ones?
Best Answer
We'va had similar issues. The reason was we had several persons editing the same shapefile on the server at the same time, which destroyed the file. Columns and rows were shifted in the .dbf. Try to avoid simultaneous access.
ArcGIS sometimes doesn't handle shapefiles correctly if the ID column is missing or empty. You should check this.