SharePoint Error: 0x80070057

Error: <nativehr>0x80070057</nativehr><nativestack></nativestack>
ObjListItem["Myname"] = "India";
ObjListItem.Update(); // error
Solution
If your Column is a lookup field, use below code.
Objitem["Myname"] = new SPFieldLookupValue(lookupItemID,lookupValue);
Or....
If your Column is ReadOnly field, use below solution
SPListItem MyItem = Mylist.Items.Add();
MyItem.Fields["MyName"].ReadOnlyField = false;
MyItem.Update();
// Then set your value
MyItem["MyName"] = "India";
MyItem.Update();