Describe the bug
I cant add a shield to my wishlist. All other items are working.

To Reproduce
Fill in the Shield. Click on Add. Error appears and Shield is not added.
The error is: Interface\AddOns\MyWishlist\source/Manager.lua:110: bad argument #1 to 'tinsert' (table expected, got nil)

Expected behavior
The Shield should be added like all other items in differnt slots.

Screenshots
No screenshot.

AddOn and Game Version:
WOTLK Classic P1

Additional context
No additional context.