Urgent - "There is no empty slots"

I have multiple free slots but still get this error.

Things I've tried that doesn't work:

• Selling Items
• Banking Items
• Buying Value Pack
• Buying +16 Inventory Slots
• /reloadui
• Moving Items in My Inventory

Check attachment below for screenshot

 

Get rid (trash) of items you don't need and then purchase Inventory Expansion Coupon +16.

 

I said above that its not possible to delete items.
It gives me "Item count is invalid"

EDIT:

I haven't played since 3 months back when I used to have maximum slots in my inventory.
The only thing I think can solve this is a value pack which I have the pearls for but can't purchase

 

You can still trash items. I tried myself just now.

 

Let me prove it to you, give me a sec and i'll record

Here is a video (Forgot to mute music recommend you mute the video to prevent ear blast).

 

You are trying to trash items from the locked inventory slots, thats why you can't. Trash that lantern oil, armor, and letter and then try.
Create new character and purchase expansion coupon +16 or value pack. It should work.

 

Tried deleting the "non locked" items as well.
I am going onto my alt to buy a value pack now to test.

Value pack on alt character fixed my issue, somewhat atleast!

 

Of course it worked.