"Item already has the maximum number of sockets" message?

Probably something obvious but I have no idea what? Tying to get six sockets on this Voll's when I get the message

"

Failed to apply item: Item already has the maximum number of sockets

However, the item only has five sockets. If I take the item to Artisan crafting bench I can add six sockets...

Items must be of a certain level to have 'X' number of sockets. Wiki entry for Sockets. The crafting benches circumvent the item level requirements for sockets.

Edit: you can find the item level for an item by holding the item on your cursor and typing /itemlevel in chat

Thanks for the information. I did wonder if it may be due to itemlevel as It's ilevel 49. I have another voll's, which is ilevel 72 and that had no issues with socket numbers.

note that you can still socket lower ilvl items, use vorici's crafting bench.