KMix just not opening on KDE Plasma, and no errors appears when running kmix on terminal

I don’t even know why this happened, but I just found this weird “bug” yesterday. I think it was because I updated my system but I don’t know.

Anyways, when I try to click on the kmix volume thing, nothing happen. I usually get a popup screen like how you would if you click on the battery icon for example.

Then, I try to open it via Application Launcher. I see KMix is there, but when I click on it, KMix showed up for like a few seconds, then it disappeared.

Then I went to the terminal and run kmix, and nothing happen. Not even errors.

After that, I tried to right click on KMix in the system tray (the little icon) in the bottom right of the screen, and some options shows up, including “Restore”, so I clicked on it.

Then, KMix does show up

After that, I tried to look around that to see what I can find, and when I click on “Settings → Audio Setup”, I see this error. I don’t know how it is related to the fact that I cannot launch KMix, but here is everything that I have right now. The fact that I don’t see any errors when I run kmix in the terminal frustrate me a lot.

Please help me out!