use version: beta-splendid-howling-boar
When it happens in a Instance.
Use new features: "Current + percent" and "Current + deficit" health text options.
seem to have no errors after switching back to the original blank and percentage.
(Sorry for my poor English)

638x Kui_Nameplates_Core\create.lua:726: attempt to concatenate a nil value
Kui_Nameplates_Core\create.lua:726: in function ?' Kui_Nameplates_Core\create.lua:731: in function <Kui_Nameplates_Core\create.lua:728> Kui_Nameplates_Core\create.lua:750: in function UpdateHealthText'
Kui_Nameplates_Core\hook.lua:114: in function func' Kui_Nameplates\messages.lua:77: in function DispatchMessage'
Kui_Nameplates\elements/healthbar.lua:95: in function UpdateHealth' Kui_Nameplates\elements/healthbar.lua:108: in function func'
Kui_Nameplates\messages.lua:123: in function <Kui_Nameplates\messages.lua:88>

Locals:
InCombatSkipped

Any instance in particular? Do you have Kui_Nameplates_Custom (or one of those scripts) or _Extras?

Do you have Kui_Nameplates_Custom (or one of those scripts) or _Extras?
NO, but have Kui_Enemy_Colors.
Any instance in particular?
This is true for many Instances. I haven't recorded it in detail. It should be all Instances.

kaay, I can't reproduce this. Can you make sure it's still happening (i.e. on the latest beta), and if it is, replace your Kui_Nameplates_Core/create.lua with this one: https://raw.githubusercontent.com/kesava-wow/kuinameplates2/issue/260/Kui_Nameplates_Core/create.lua, and see if that fixes it.

Have downloaded the latest beta, and replaced Kui_Nameplates_Core/create.lua, Wait until I'm free to instance test.

That modification helped, but I still can't reproduce this regardless, even in antorus. As far as I can tell, something else is calling one of my frame's functions before it's ready. That should be the only way this is possible. Specifically, something is calling f.UpdateHealthText.

I know it's annoying to do this but can you test it with every addon disabled, leaving just Kui_Nameplates, Kui_Nameplates_Core and Kui_Nameplates_Core_Config enabled?

Thanks.

I have tested it in (Antorus, the Burning Throne)，No more large number errors, Only one error occurred.(Perhaps this is because there are fewer mobs)

1x Kui_Nameplates_Core\create.lua:732: attempt to concatenate a nil value
Kui_Nameplates_Core\create.lua:732: in function ?' Kui_Nameplates_Core\create.lua:737: in function <Kui_Nameplates_Core\create.lua:734> Kui_Nameplates_Core\create.lua:760: in function UpdateHealthText'
Kui_Nameplates_Core\hook.lua:114: in function func' Kui_Nameplates\messages.lua:77: in function DispatchMessage'
Kui_Nameplates\elements/healthbar.lua:95: in function UpdateHealth' Kui_Nameplates\elements/healthbar.lua:108: in function func'
Kui_Nameplates\messages.lua:123: in function <Kui_Nameplates\messages.lua:88>

Locals:
InCombatSkipped

Already used to using various addons, It's a bit difficult now for me not to use addons, Especially in the instance.

Can only say that I try to do the test in the outdoor, Try to kill some mobs, When I'm more free.

Thank you for your response and corrected the problem. Although not 100% resolved, thank you!

I have already tested kill mobs outdoors and still have errors.
Only use the following addons:
!BugGrabber
BugSack
Bazooka
Kui_Nameplates
Kui_Nameplates_Core
Kui_Nameplates_Core_Config

version:
beta-caring-spider-giggling-tiger
replaced Kui_Nameplates_Core/create.lua
Setting:
health_text_hostile_max = maximum
health_text_hostile_dmg = Current + percent
All friendly = Blank

The error is as follows:
2x Kui_Nameplates_Core\create.lua:731: attempt to concatenate a nil value
Kui_Nameplates_Core\create.lua:731: in function ?' Kui_Nameplates_Core\create.lua:737: in function <Kui_Nameplates_Core\create.lua:734> Kui_Nameplates_Core\create.lua:760: in function UpdateHealthText'
Kui_Nameplates_Core\hook.lua:114: in function func' Kui_Nameplates\messages.lua:77: in function DispatchMessage'
Kui_Nameplates\elements/healthbar.lua:95: in function UpdateHealth' Kui_Nameplates\elements/healthbar.lua:108: in function func'
Kui_Nameplates\messages.lua:123: in function <Kui_Nameplates\messages.lua:88>

Locals:
InCombatSkipped

Ok. I've updated the create.lua so it should stop all those errors for you: https://raw.githubusercontent.com/kesava-wow/kuinameplates2/issue/260/Kui_Nameplates_Core/create.lua

I still can't reproduce this (even on the zhTW and zhCN clients), don't understand how it could be happening, haven't had any other reports of it, and this is an inefficient workaround. So I don't want to put it in the main addon (which would then make finding the cause more difficult).

My only suggestion at this point would be to try making a new profile in KNP (and applying your health text settings of course) aand perhaps deleting all the KNP folders and re-installing it. Otherwise, I just need to wait for anyone else to report it so that I can try to work out what's happening.

Thanks.

Thank you very much for your efforts, I don't know how it happened. Maybe it's just my case.
I will continue to try. In short don't worry too much, thank you!

OMG! I reinstall the KNP and delete all profiles, then there is an error when logging in, the KNP instruction has no effect, and the options in the interface are completely invisible.

What happened? The error is as follows:

1x Kui_Nameplates_Core\config.lua:786: attempt to index global 'KuiNameplatesCoreSaved' (a nil value)
Kui_Nameplates_Core\config.lua:786: in function InitialiseConfig' Kui_Nameplates_Core\hook.lua:268: in function Initialise'
Kui_Nameplates\addon.lua:149: in function <Kui_Nameplates\addon.lua:115>

Locals:
self =

Fixed that in beta-beaming-snake-caring-puppy.

I installed the beta-beaming-snake-caring-puppy, and replaced Kui_Nameplates_Core/create.lua
Into a Instance test (Mythic+), no more errors. maybe it's also possible that I reinstall and delete all profiles.
Thank you for your help !

I'm relatively sure this is no longer an issue.