I'm having this issue too. I'm a sub (payment went out on the 30th of nov) and it wont let me equip any purple banded items. Like the poster who put the pic above, it says I don't have the subscribers permission!?

Additional: This restriction does not carry to companions. I tried the same piece of equiptment on my companion and he was able to wear it.

I have relogged twice with no success on the matter

I have filed a bug report stating the facts above.