What are yo udoing int he code that says, "". I am skeptical that this error is occurring when you call "myshape->DestroyEntity, ent". I think this error typically occurs when running a classification using ENVI. I wonder if that might be the cause of your issue?

The code that extract statistics consists on these steps: Create a new shapefile with only the selected entity with its attributes Add the .prj file copying it from the original Open the new shapefile with IDLffShape and GetAttribute Extact the records Open the new shapefile with OpenVector Create a new Roi with EnviRoi Add the record using AddVectorRecords, myvector, record Save the roi as xml file Open the new roi xml file Use the EnviRoiMaskRaster(my_raster, roi_xml) command Use ENVIRasterStatistics (masked_raster) to obtain the mean as Stats.Mean Now i tryed to execute the command: IF (Stats.Mean LT 7000) THEN myshape->DestroyEntity, ent Then i tryed to do another thing: create a roi.xml from the original shapefile i want modified to delete the corresponding VectorRecords using the code: IF (Stats.Mean LT 7000) THEN rois_xml.ClearVectorRecords, myvector where rois_xml is a roi.xml file corresponding to the first shapefile opened before the FOR cicle and named myshape (see previous post). This code does not exit with an error but does nothing and does not modify the rois_xml file. If you want to see the full code ask me. But my need is simple: i want cicle inside a vector of polygons, compute the mean over a raster for each polygon, apply a condition (mean less then 7000), delete the corresponding entity from the shapefile, save the new shapefile. Using vector utilities or roi utilities or both it's the same thing for me.