Hearal of thunder stopped working

Hello

I have a Huntress that I have been playing for a long while now. For some reason My 5 socket Herald of thunder spirit gem has stopped working. There hasn't been anything I have changed with my character. I have 150 spirit, 120 dex and am using a spear and shield. But for some reason now It is saying "it will not work with the current weapons settings". I haven't changed anything I don't understand. It just stopped all of a sudden. I can say I did unequipped my shield and re-equip it. Which changed my stats of a second. I verified with other Herald gems and they work just fine. My current Herald of Thunder gem is rank 14, 20% with 5 sockets.

Please help I have spent a lot of time getting it to this point.

Sincerely

Anthony

Click the arrow next to the dps value and make sure at least one weapon set is selected.