I have upgraded my existing project to version 6.0.0 from 4.11.10, In that project custom section was already there with tree nodes displayed when clicking on custom section, but now when i click on custom section, tree nodes in that custom section (Hierarchy) are not loading after project upgraded to v6.0.0, i also checked in firebug, and it displays ajax call that is called like this:

http://localhost:8089/umbraco/webservices/TreeDataService.ashx?rnd=a25ab19e94cf4a6898d0016345220c9c&id=-1&contextMenu=true&isDialog=false&app=customsection&rnd2=70.1

Here i think id is -1, i don't know why but error must be because of id is -1 but i don't know the solution and also i am getting array empty here in firebug: http://localhost:8089/umbraco/uComponents/Items/range

Please help, Thanks in advance :)