Started playing with QGIS recently and I have encountered a problem. I have a layer with administrative areas of my country and when adding it the encoding is set to UTF-8. When I open its attribute table the feature names are jumbled and special characters are replaced with symbols. Also, when I try to use intersection with another layer i get the following message: Input layer A contains invalid geometries (feature 56). Unable to complete intersection algorithm.
I tried with 32 and 64 bit version of QGIS 2.18.9. I'm running Windows 10. The catch is, a friend of mine is using QGIS 2.14.2 on Windows 10, and didn't have any problems with encoding (her attribute tables are fine) or intersection (works without any error messages) while using the same SHP files.
What could be the problem?