Invalid Geometry

[souravs89]

I am extremely grateful for the free availability of Assembly and Parliamentary constituency, States and district shapefiles of India. Most operations can be done with them. However, the intersection feature doesn't seem to work since there are invalid geometries. Additional work, for instance with Check Validity option in QGIS or "clgeo_Clean" function of cleangeo package in R seem to validate the files (for instance the geometry validator reports zero errors). However, although the Admin2 works well with intersection after "clgeo_Clean", the parliamentary and assembly constituencies and district files still do not seem to work well with intersection. Has anyone experienced such issues before? Thank you very much!