Missing icons after updating to Plasma 6

Hi! I just recently switched from Garuda with Cinnamon to Arch with KDE Plasma. So far I’m a massive fan. Everything is very easy to work with, responsive and it feels like a very smooth desktop experience.

However, I first installed Plasma 5 about a month ago and recently updated to Plasma 6 which sent most taskbar icons to the purgatory as seen in the picture.

How can I fix this? I already reinstalled Plasma 6 and nothing changed.

inxi -Full gives me:

System:
  Host: G14 Kernel: 6.7.9-arch1-1 arch: x86_64 bits: 64
  Desktop: KDE Plasma v: 6.0.2 Distro: Arch Linux
Machine:
  Type: Laptop System: ASUSTeK product: ROG Zephyrus G14
    GA401QM_GA401QM v: 1.0 serial: <superuser required>
  Mobo: ASUSTeK model: GA401QM v: 1.0 serial: <superuser required>
    uuid: <superuser required> UEFI: American Megatrends LLC.
    v: GA401QM.412 date: 08/30/2022
Battery:
  ID-1: BAT0 charge: 55.7 Wh (100.5%) condition: 55.4/76.0 Wh (72.9%)
    volts: 15.8 min: 15.8
  ID-2: hidpp_battery_3 charge: 94% condition: N/A
CPU:
  Info: 8-core model: AMD Ryzen 9 5900HS with Radeon Graphics bits: 64
    type: MT MCP cache: L2: 4 MiB
  Speed (MHz): avg: 2075 min/max: 400/4680 cores: 1: 3502 2: 400
    3: 3556 4: 3513 5: 4381 6: 400 7: 400 8: 3494 9: 400 10: 400
    11: 3614 12: 3688 13: 4252 14: 400 15: 400 16: 400
Graphics:
  Device-1: NVIDIA GA106M [GeForce RTX 3060 Mobile / Max-Q]
    driver: nvidia v: 550.54.14
  Device-2: AMD Cezanne [Radeon Vega Series / Radeon Mobile Series]
    driver: amdgpu v: kernel
  Display: x11 server: X.Org v: 21.1.11 with: Xwayland v: 23.2.4
    driver: X: loaded: amdgpu,nvidia unloaded: modesetting dri: radeonsi
    gpu: amdgpu,nvidia,nvidia-nvswitch resolution: 1: 3440x1440
    2: 1920x1080~144Hz
  API: EGL v: 1.5 drivers: nvidia,radeonsi,swrast
    platforms: gbm,x11,surfaceless,device
  API: OpenGL v: 4.6.0 compat-v: 4.5 vendor: amd mesa
    v: 24.0.3-arch1.1 renderer: AMD Radeon Graphics (radeonsi renoir
    LLVM 17.0.6 DRM 3.57 6.7.9-arch1-1)
  API: Vulkan v: 1.3.279 drivers: nvidia,radv surfaces: xcb,xlib
Audio:
  Device-1: NVIDIA GA106 High Definition Audio driver: snd_hda_intel
  Device-2: AMD Renoir Radeon High Definition Audio
    driver: snd_hda_intel
  Device-3: AMD ACP/ACP3X/ACP6x Audio Coprocessor driver: N/A
  Device-4: AMD Family 17h/19h HD Audio driver: snd_hda_intel
  Device-5: Generic USB Audio
    driver: hid-generic,snd-usb-audio,usbhid type: USB
  API: ALSA v: k6.7.9-arch1-1 status: kernel-api
  Server-1: PipeWire v: 1.0.4 status: active
Network:
  Device-1: MEDIATEK MT7921 802.11ax PCI Express Wireless Network
    Adapter driver: mt7921e
  IF: wlan0 state: up mac: ec:2e:98:ca:ff:07
Bluetooth:
  Device-1: MediaTek Wireless_Device driver: btusb type: USB
  Report: btmgmt ID: hci0 rfk-id: 0 state: down
    bt-service: enabled,running rfk-block: hardware: no software: yes
    address: EC:2E:98:CA:FF:06 bt-v: 5.2
Drives:
  Local Storage: total: 476.94 GiB used: 165.34 GiB (34.7%)
  ID-1: /dev/nvme0n1 vendor: Samsung model: MZVLQ512HBLU-00B00
    size: 476.94 GiB
Partition:
  ID-1: / size: 476.42 GiB used: 165.04 GiB (34.6%) fs: btrfs
    dev: /dev/dm-0 label: N/A uuid: N/A
  ID-2: /boot size: 511 MiB used: 313.9 MiB (61.4%) fs: vfat
    dev: /dev/nvme0n1p1 label: N/A uuid: 574B-551E
  ID-3: /home size: 476.42 GiB used: 165.04 GiB (34.6%) fs: btrfs
    dev: /dev/dm-0 label: N/A uuid: N/A
  ID-4: /var/log size: 476.42 GiB used: 165.04 GiB (34.6%) fs: btrfs
    dev: /dev/dm-0 label: N/A uuid: N/A
Swap:
  ID-1: swap-1 type: zram size: 4 GiB used: 1.17 GiB (29.3%)
    dev: /dev/zram0
Sensors:
  System Temperatures: cpu: 90.9 C mobo: 58.0 C gpu: amdgpu
    temp: 68.0 C
  Fan Speeds (rpm): cpu: 4100
Info:
  Memory: total: 16 GiB note: est. available: 15.03 GiB
    used: 9.08 GiB (60.4%)
  Processes: 403 Uptime: 2d 22h 6m Shell: fish inxi: 3.3.33

It means your icons package is not plasma 6 ready. You can install icons theme that is ready for plasma 6 or ignore the missing icons until your installed icons theme updated to plasma 6 ready. That’s the problem that come along with major version upgrade.