Function only avaible to Blizzard UI?

[ZMasterJZ]

I've been making a new PlayerFrame and stumbled into an error message that came up after using blizzard code to make my addon. It happens when you click the health and mana bars,
which use this script:

<OnMouseUp>
this:GetParent():Click(button);
</OnMouseUp>

if I disable the script, theres no problems (nor anything that happens if you click, of course).
This script is in both the Health and Mana status bars, and I was wondering why it gives me such an error as "A Addon is trying to use a function only avaible to blizzard UI" with options to "disable UI" or "ignore"

and what way I could just this script to keep the functionality by using a different script.

Thanks, ZMaster