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when I import new layers, it can happen that the coordinate system is changing – in that case I can’t see one or more layers and of course can’t work with them. Why is this happening and how can I prevent it?

marked as duplicate by underdark qgis Jul 27 '18 at 15:52

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  • Do you know the coordinate system of your datasets and have you set your project CRS? – AWGIS Jul 25 '18 at 7:42

Sounds like you project switches to the new layers coordinate reference system (CRS). A CRS "tells", how exactly data is to be displayed, where exactly it is situated etc. Different CRS display the same data differently, in the worst case not at all.

Go to Options and the tab CRS, make sure that CRS for new projects is set to the middle bulletin ("on the fly reprojection") and that CRS for new layers is set to the middle bulletin ("use project CRS") also.

  • 1
    This feature is called On-the-fly Reprojection, sometimes abbreviated as OTF Reprojection. In QGIS 3 and later, OTF Reprojection is always on. – csk Jul 25 '18 at 19:07

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