A call stack would help, but a a 36 appearing there sounds like someone is calling drawText on Window_Base as if it was the method on Bitmap. The former doesn’t have a lineHeight parameter preceding align.
I’m pretty certain that this line here in Window_EquipSlot.prototype.drawItem is the culprit:

The bug is present in both MV and MZ, but fixed in the YEP_EquipCore.
You can just delete the , this.lineHeight() part there to fix this, but I’ll make plugin to auto-check that argument tomorrow, too.