!! Changed the title after problem got specified !!!
Hello 
(this might be a bug thus in the wrong category)
I imported a model from the toolbox. It glows (I don’t know why, but it glows^^) as long as I leave it in workspace.
I can parent it to any part I want except models that contain a Humanoid.
Then it looses its glow.
Below is a picture of what I mean. This happened to other models with this glow effect as well.
Does anyone know why this is happening?
Thanks
Branghello
Can you send a link to the model?
Yes
One thing I noticed when I got the links is that the toolbox also shows the models without a glow. However I like the glow 
The model I posted a screenschot of:
https://create.roblox.com/marketplace/asset/61969087/Disco-Racing-Helmet
The other model:
https://create.roblox.com/marketplace/asset/19171980/Berserker-helmet
It looks like the model gets it’s glow by giving itself a VertexColor higher than 1, making it technically “brighter than white” or “redder than red” in this case I suppose, which, given that Roblox supports HDR, makes it glow like neon.
As for why it doesn’t work with humanoids, I don’t know. It could be that humanoids just don’t have the HDR effect because of an oversight.
Thank you very much for your efforts
I did not know about VertexColor which seems quite useful for the future.
I wish there was a solution to my issue, but I guess your are correct with the oversight.
Still weird that the issue arises even when the humanoid and the glowing mesh are just siblings.
Maybe I will create a separate post regarding this - for now I will consider my problem to be done.
Thanks again