Hi Mark Do remember the reason for having cityList and cites in PlacesFile. In 854 you introduced the cityList in addition to the pre-existing cities list. The cities list became a list of unique city names per country. There is a problem that cityList.size() is the actual number of city records written to LBL, but the number cities.size() is used whenever you need to know how many cities there are, which is usually less than cityList.size(). The problem occurs when cityList.size() is > 255 but cites.size() is less than 256, when the cities get written as one byte values rather than two bytes ones. The number of cities is used in NET1 too and so affects that unless the difference is intentional for NET1. So do you think it is safe to use cityList.size() where ever the number of cites is required as in the attached patch? Everyone having assertion failures creating index files could try the patch out and see if it helps. You will have to re-create the .img file with this patch applied, not just the index. ..Steve