Disabling my addon gives this error:

RuntimeError: unregister_class(...):, missing bl_rna attribute from 'RNAMeta' instance (may not be registered)

and re-enabling it gives this error:

ValueError: register_class(...): already registered as a subclass

It did this before but as of the 2.8 release the panel is not getting updated.

I don't know why the register and unregister are failing, I am registering it like this:

classes = (
D_Some_Variables,
D_OT_Some_Op
D_PT_Some_Panel,
)

def register():
for cls in classes:
bpy.utils.register_class(cls)
bpy.types.Scene.some_vars = bpy.props.PointerProperty(type = Some_Variables)

def unregister():
del bpy.types.Scene.some_vars
for cls in reversed(classes):
bpy.utils.unregister_class(cls)

• The code itself seems to be ok, but apparently you're trying to unregister something that doesn't exist anymore. This is likely caused by some code not shown in your questions. Perhaps this may help for debugging: blender.stackexchange.com/questions/19249/… – Robert Gützkow Nov 16 '19 at 9:53