NCache 4.6 - Online Documentation

Updating an Item in a Data Group

If you add an item without any group or want to group an already cached item, you have to first remove that item from the cache and then Insert/Add that item with the desired group and sub group identifiers. Otherwise, the insert operation throws a data groups mismatch exception.
In other words, you can not directly update an item in a Group in in NCache.
See Also