c# - Dictionary error while removing two time the same index -

i've problem dictionary. it's said in title, i'm getting error everytime i'm trying delete same index 2 time in row.

id have dictionary of 60 entries, , remove entry 0, entry 1 should became entry 0, 2 entry 1,... should able delete entry 0 time, no ?

maybe i'm wrong, , can tell me how work ?

ps:i'm using remove() function.

        foreach (var item in classboxlist)         {             uint classid = 0;             bool contain = false;             uint index = 0;             uint = 0;              foreach (var charclass in dbcstores.chrclasses.records)             {                 if (charclass.name.string == item.name)                     classid = charclass.classid;             }              charbaseinfoentry charclassrace = new charbaseinfoentry() { raceid = (byte)raceid, classeid = (byte)classid };              foreach (var t in dbcstores.charbaseinfo.records)             {                 if (t.classeid == classid && t.raceid == raceid)                 {                     contain = true;                     index = i;                 }                  i++;             }              if (contain)             {                 if (item.selectedindex == 0)                 {                     //remove race/class entry                     messagebox.show(index+" -- "+ dbcstores.charbaseinfo.records.count.tostring());                     dbcstores.charbaseinfo.removeentry(index);                 }             }             else             {                 if (item.selectedindex == 1)                 {                     //add new race/class entry                     dbcstores.charbaseinfo.addentry(dbcstores.charbaseinfo.maxkey + 1, charclassrace);                 }             }         }       public void removeentry(uint id)     {         if (!mrecords.containskey(id))             throw new exception("cette clé n'existe pas !");          isedited = true;         mrecords.remove(id);     } 

you're not removing entry given index entry has given key

that, , in dictionary key unique trying remove 2 times in row same key nonsense (unless re-added somewhere else in meantime)