Weirdness with healing potions

Hey all,
I have a 'potion' in a game that heals the user between 10-15 HP. It works fine...until the player has no weapon equipped. At that point, instead of healing the player, it deals 1 damage to them instead. Very weird. Why would this happen?

Here's how I have it set up:

Because you have some plugin that alters how this works. Turn off all your plugins and verify that the potion works correctly. Then turn them off one by one in order of which is most probable to cause the issue. Eventually you'll find which one it is :)

nothing in default or in that item can do this, so something messed up your data - show us a screenshot of your plugin manager and we might find the cause

Ok, here's the plugins that change or alter damage or items in some way:

your plugin order for yanfly plugins is completely wrong.
please reorder them according to the list on yanfly's website, delete or ignore all older savegames and start a new game to check if the error is gone then.

Nope, sorted them exactly as on the Yanfly's website plugin order, still happens.

then show us your full list of plugin as it is re-sorted now - the screenshot above only contained some of your plugins.
Something in there is causing the problem, and if the full list doesn't show any known compatibilities anymore then you'll have to test by disabling them one after another (always starting a new game after each change in the plugin manager)

Just curious...is there a way to raise a player's HP by randomly 10-15 in the notetags area of the item? Meaning not connected to 'damage' in this case?

@SimProse
Notetags by themselves have absolutely no function at all.
What happens is that if a plugin reads a notetag that knows it, then it can follow those instructions it already knows.

So if you have or request a plugin that does this raising then the answer is yes.
Without a plugin for that the answer is no.