I can't use armor or weapons

I started the Fate of the Vaal league in Standard and I can't use my Forked Spear, a pair of Wisdom Gloves, and some unusual boots I have equipped on my character. I've changed my skill tree and added Dexterity, Intelligence, and Strength nodes, but it still doesn't work. What's surprising is that I have another Forked Spear, another pair of Wisdom Gloves, and similar boots, and it lets me equip those, but not the others. It doesn't make sense. Please help.

I should clarify that I have Spear skills, and it won't let me use that specific Forked Spear. I can use the other one, but I can't use the Wisdom Gloves, although I can use other pairs of Wisdom Gloves. The same thing happens with the boots.