There are many posts on this but I was wondering on which layer should I do my operations. I explain: I am using the Corine Land Cover (CLC) files for 2006 and I am just interested in one part in Germany. So I did an intersection between my layer with entire europe and the one with an adm area. In the log I can see that I have many invalid geometries and as a result I am losing a lot of objects.
How can I fix that and on which layer should I act upon (the CLC layer which is very big?)
Could it be due because the CLC files are rasters rather than vectors?