"Unknown application folder" when launching from task bar

I try to launch Konqueror from its ‘pinned to task manager’ icon and all that happens is this error:
Screenshot_2023-03-02_10:36:52-1

It happens only with Konqueror; other apps (tested: Discover, Firefox, Betterbird, Kate, KWrite, Konsole) launch as expected.

The issue exists with alternative task managers (tested: Tasks Manager, Icons-only Task Manger, Fancy Tasks).

Removing the icon from task manager and re-pinning from running Konqueror does not help.

Konqueror is called with --open-session unsplit '1>&-' '2>&-' '&', but removing that does not help.

Launching Konqueror from a separate widget, from desktop, from Launcher, or from custom shortcut does work as expected.

Must be something between Konqueror and the task managers. Where/how can I fix that?

Edit:
Operating System: Manjaro Linux
KDE Plasma Version: 5.26.5
KDE Frameworks Version: 5.103.0
Qt Version: 5.15.8
Kernel Version: 6.1.12-1-MANJARO (64-bit)
Graphics Platform: X11

Update:
I completely removed and reinstalled Konqueror. Problem persisted.

Then created a fresh user, logged in there, changed only mouse, keyboard layout, and taskbar (from icons-only taskbar to fancy taskbar). The task bar already had a konqueror icon which launched konqueror to the default start page.

I pinned its window to the taskbar (via context menu), so now there were two konqueror icons. The original one launched the browser, while the new one sent the error notification. They were listed differently in ~/.config/plasma-org.kde.plasma.desktop-appletsrc, under

[Containments][2][Applets][71][Configuration][General]
[...]
launchers=[...]preferred://browser,[...]applications:org.kde.konqueror.desktop

Switched back to ususal user, created a .desktop in ~/Desktop/ via launcher worked as expected.

So the problem is not the konqueror install, but that it is not responsive to whatever is its .desktop correlate applications:org.kde.konqueror.desktop in task manager.

Please, do you have any ideas on how to proceed to make konqueror pinned to task bar launchable from there?

inxi says:

Summary
System:
  Kernel: 6.1.12-1-MANJARO arch: x86_64 bits: 64 compiler: gcc v: 12.2.1
    parameters: BOOT_IMAGE=/@/boot/vmlinuz-6.1-x86_64
    root=UUID=2b1a4208-2996-40a0-b702-a19bf2299ab8 rw rootflags=subvol=@
    cryptdevice=UUID=553d95f9-e962-49ed-b6e7-bee7726a5ec1:luks-553d95f9-e962-49ed-b6e7-bee7726a5ec1
    root=/dev/mapper/luks-553d95f9-e962-49ed-b6e7-bee7726a5ec1
    resume=/dev/mapper/luks-13f9c137-c427-4be0-b567-33a209509780
    udev.log_priority=3
  Desktop: KDE Plasma v: 5.26.5 tk: Qt v: 5.15.8 wm: kwin_x11 vt: 1 dm: SDDM
    Distro: Manjaro Linux base: Arch Linux
Machine:
  Type: Laptop System: Framework product: Laptop v: AB
    serial: <superuser required>
  Mobo: Framework model: FRANBMCP0B v: AB serial: <superuser required>
    UEFI: INSYDE v: 03.10 date: 07/19/2022
Battery:
  ID-1: BAT1 charge: 41.0 Wh (80.7%) condition: 50.8/55.0 Wh (92.4%)
    volts: 16.6 min: 15.4 model: NVT Framewo type: Li-ion serial: <filter>
    status: charging cycles: 27
  Device-1: apple_mfi_fastcharge model: N/A serial: N/A charge: N/A
    status: N/A
Memory:
  RAM: total: 31.14 GiB used: 4.76 GiB (15.3%)
  RAM Report: permissions: Unable to run dmidecode. Root privileges required.
CPU:
  Info: model: 11th Gen Intel Core i7-1165G7 bits: 64 type: MT MCP
    arch: Tiger Lake gen: core 11 level: v4 note: check built: 2020
    process: Intel 10nm family: 6 model-id: 0x8C (140) stepping: 1
    microcode: 0xA6
  Topology: cpus: 1x cores: 4 tpc: 2 threads: 8 smt: enabled cache:
    L1: 320 KiB desc: d-4x48 KiB; i-4x32 KiB L2: 5 MiB desc: 4x1.2 MiB L3: 12 MiB
    desc: 1x12 MiB
  Speed (MHz): avg: 1002 high: 2800 min/max: 400/4700 scaling:
    driver: intel_pstate governor: powersave cores: 1: 783 2: 882 3: 717 4: 788
    5: 585 6: 2800 7: 614 8: 847 bogomips: 44864
  Flags: 3dnowprefetch abm acpi adx aes aperfmperf apic arat
    arch_capabilities arch_perfmon art avx avx2 avx512_bitalg avx512_vbmi2
    avx512_vnni avx512_vp2intersect avx512_vpopcntdq avx512bw avx512cd
    avx512dq avx512f avx512ifma avx512vbmi avx512vl bmi1 bmi2 bts cat_l2
    cdp_l2 clflush clflushopt clwb cmov constant_tsc cpuid cpuid_fault cx16
    cx8 de ds_cpl dtes64 dtherm dts epb ept ept_ad erms est f16c flexpriority
    flush_l1d fma fpu fsgsbase fsrm fxsr gfni ht hwp hwp_act_window hwp_epp
    hwp_notify hwp_pkg_req ibpb ibrs ibrs_enhanced ibt ida intel_pt invpcid
    invpcid_single lahf_lm lm mca mce md_clear mmx monitor movbe movdir64b
    movdiri msr mtrr nonstop_tsc nopl nx ospke pae pat pbe pcid pclmulqdq pdcm
    pdpe1gb pebs pge pku pln pni popcnt pse pse36 pts rdpid rdrand rdseed
    rdt_a rdtscp rep_good sdbg sep sha_ni smap smep split_lock_detect ss ssbd
    sse sse2 sse4_1 sse4_2 ssse3 stibp syscall tm tm2 tpr_shadow tsc
    tsc_adjust tsc_deadline_timer tsc_known_freq umip vaes vme vmx vnmi
    vpclmulqdq vpid x2apic xgetbv1 xsave xsavec xsaveopt xsaves xtopology xtpr
  Vulnerabilities:
  Type: itlb_multihit status: Not affected
  Type: l1tf status: Not affected
  Type: mds status: Not affected
  Type: meltdown status: Not affected
  Type: mmio_stale_data status: Not affected
  Type: retbleed status: Not affected
  Type: spec_store_bypass mitigation: Speculative Store Bypass disabled via
    prctl
  Type: spectre_v1 mitigation: usercopy/swapgs barriers and __user pointer
    sanitization
  Type: spectre_v2 mitigation: Enhanced IBRS, IBPB: conditional, RSB
    filling, PBRSB-eIBRS: SW sequence
  Type: srbds status: Not affected
  Type: tsx_async_abort status: Not affected
Graphics:
  Device-1: Intel TigerLake-LP GT2 [Iris Xe Graphics] driver: i915 v: kernel
    arch: Gen-12.1 process: Intel 10nm built: 2020-21 ports: active: eDP-1
    empty: DP-1, DP-2, DP-3, DP-4 bus-ID: 00:02.0 chip-ID: 8086:9a49
    class-ID: 0300
  Display: x11 server: X.Org v: 21.1.7 compositor: kwin_x11 driver: X:
    loaded: modesetting alternate: fbdev,vesa dri: iris gpu: i915 display-ID: :0
    screens: 1
  Screen-1: 0 s-res: 2256x1504 s-dpi: 96 s-size: 596x397mm (23.46x15.63")
    s-diag: 716mm (28.19")
  Monitor-1: eDP-1 model: BOE Display 0x095f built: 2019 res: 2256x1504
    hz: 60 dpi: 201 gamma: 1.2 size: 285x190mm (11.22x7.48") diag: 343mm (13.5")
    ratio: 3:2 modes: 2256x1504
  API: OpenGL v: 4.6 Mesa 22.3.5 renderer: Mesa Intel Xe Graphics (TGL GT2)
    direct-render: Yes
Audio:
  Device-1: Intel Tiger Lake-LP Smart Sound Audio driver: snd_hda_intel
    v: kernel alternate: snd_sof_pci_intel_tgl bus-ID: 00:1f.3 chip-ID: 8086:a0c8
    class-ID: 0403
  Sound API: ALSA v: k6.1.12-1-MANJARO running: yes
  Sound Server-1: JACK v: 1.9.22 running: no
  Sound Server-2: PulseAudio v: 16.1 running: yes
  Sound Server-3: PipeWire v: 0.3.65 running: yes
Network:
  Device-1: Intel Wi-Fi 6 AX210/AX211/AX411 160MHz driver: iwlwifi v: kernel
    pcie: gen: 2 speed: 5 GT/s lanes: 1 bus-ID: aa:00.0 chip-ID: 8086:2725
    class-ID: 0280
  IF: wlp170s0 state: up mac: <filter>
  IP v4: <filter> type: dynamic noprefixroute scope: global
    broadcast: <filter>
  IP v6: <filter> type: dynamic noprefixroute scope: global
  IP v6: <filter> type: noprefixroute scope: link
  Device-2: Realtek RTL8153 Gigabit Ethernet Adapter type: USB driver: r8152
    bus-ID: 2-3.3:5 chip-ID: 0bda:8153 class-ID: 0000 serial: <filter>
  IF: enp0s13f0u3u3 state: down mac: <filter>
  IF-ID-1: eth0 state: down mac: <filter>
  WAN IP: <filter>
Bluetooth:
  Device-1: Intel AX210 Bluetooth type: USB driver: btusb v: 0.8 bus-ID: 3-10:8
    chip-ID: 8087:0032 class-ID: e001
  Report: rfkill ID: hci0 rfk-id: 1 state: up address: see --recommends
Logical:
  Message: No logical block device data found.
  Device-1: m-backupssd maj-min: 254:2 type: LUKS dm: dm-2 size: 931.51 GiB
  Components:
  p-1: sdb1 maj-min: 8:17 size: 931.51 GiB
  Device-2: luks-553d95f9-e962-49ed-b6e7-bee7726a5ec1 maj-min: 254:0
    type: LUKS dm: dm-0 size: 896.96 GiB
  Components:
  p-1: nvme0n1p2 maj-min: 259:2 size: 896.96 GiB
  Device-3: luks-13f9c137-c427-4be0-b567-33a209509780 maj-min: 254:1
    type: LUKS dm: dm-1 size: 34.25 GiB
  Components:
  p-1: nvme0n1p3 maj-min: 259:3 size: 34.26 GiB
RAID:
  Message: No RAID data found.
Drives:
  Local Storage: total: 2.69 TiB used: 729.56 GiB (26.5%)
  SMART Message: Unable to run smartctl. Root privileges required.
  ID-1: /dev/nvme0n1 maj-min: 259:0 vendor: Western Digital
    model: WDS100T1X0E-00AFY0 size: 931.51 GiB block-size: physical: 512 B
    logical: 512 B speed: 63.2 Gb/s lanes: 4 type: SSD serial: <filter>
    rev: 614900WD temp: 36.9 C scheme: GPT
  ID-2: /dev/sda maj-min: 8:0 type: USB model: N/A size: 894.25 GiB
    block-size: physical: 4096 B logical: 512 B type: N/A serial: N/A rev: 0204
    scheme: GPT
  ID-3: /dev/sdb maj-min: 8:16 type: USB vendor: Sabrent model: SABRENT
    size: 931.51 GiB block-size: physical: 4096 B logical: 512 B type: N/A
    serial: <filter> rev: 0204 scheme: GPT
  Message: No optical or floppy data found.
Partition:
  ID-1: / raw-size: 896.96 GiB size: 896.96 GiB (100.00%)
    used: 371.52 GiB (41.4%) fs: btrfs dev: /dev/dm-0 maj-min: 254:0
    mapped: luks-553d95f9-e962-49ed-b6e7-bee7726a5ec1 label: N/A
    uuid: 2b1a4208-2996-40a0-b702-a19bf2299ab8
  ID-2: /boot/efi raw-size: 300 MiB size: 299.4 MiB (99.80%)
    used: 752 KiB (0.2%) fs: vfat dev: /dev/nvme0n1p1 maj-min: 259:1 label: N/A
    uuid: 71A5-1BE9
  ID-3: /home raw-size: 896.96 GiB size: 896.96 GiB (100.00%)
    used: 371.52 GiB (41.4%) fs: btrfs dev: /dev/dm-0 maj-min: 254:0
    mapped: luks-553d95f9-e962-49ed-b6e7-bee7726a5ec1 label: N/A
    uuid: 2b1a4208-2996-40a0-b702-a19bf2299ab8
  ID-4: /run/media/luksdevices.d/backupssd raw-size: 931.51 GiB
    size: 931.51 GiB (100.00%) used: 320.41 GiB (34.4%) fs: btrfs dev: /dev/dm-2
    maj-min: 254:2 mapped: m-backupssd label: N/A uuid: N/A
  ID-5: /run/media/<user>/<disk> raw-size: 894.25 GiB
    size: 894.25 GiB (100.00%) used: 37.63 GiB (4.2%) fs: btrfs dev: /dev/sda1
    maj-min: 8:1 label: FilmeMTP uuid: be568a7b-b645-4365-9832-33e325bbaa75
  ID-6: /var/cache raw-size: 896.96 GiB size: 896.96 GiB (100.00%)
    used: 371.52 GiB (41.4%) fs: btrfs dev: /dev/dm-0 maj-min: 254:0
    mapped: luks-553d95f9-e962-49ed-b6e7-bee7726a5ec1 label: N/A
    uuid: 2b1a4208-2996-40a0-b702-a19bf2299ab8
  ID-7: /var/log raw-size: 896.96 GiB size: 896.96 GiB (100.00%)
    used: 371.52 GiB (41.4%) fs: btrfs dev: /dev/dm-0 maj-min: 254:0
    mapped: luks-553d95f9-e962-49ed-b6e7-bee7726a5ec1 label: N/A
    uuid: 2b1a4208-2996-40a0-b702-a19bf2299ab8
Swap:
  Kernel: swappiness: 60 (default) cache-pressure: 100 (default)
  ID-1: swap-1 type: partition size: 34.25 GiB used: 0 KiB (0.0%)
    priority: -2 dev: /dev/dm-1 maj-min: 254:1
    mapped: luks-13f9c137-c427-4be0-b567-33a209509780 label: swap
    uuid: c2e50936-bd66-4905-844f-c316bc3474fd
Unmounted:
  Message: No unmounted partitions found.
USB:
  Hub-1: 1-0:1 info: Hi-speed hub with single TT ports: 1 rev: 2.0
    speed: 480 Mb/s chip-ID: 1d6b:0002 class-ID: 0900
  Hub-2: 2-0:1 info: Super-speed hub ports: 4 rev: 3.1 speed: 10 Gb/s
    chip-ID: 1d6b:0003 class-ID: 0900
  Device-1: 2-1:7 info: JMicron / USA JMS561U two ports SATA 6Gb/s bridge
    type: Mass Storage driver: uas interfaces: 1 rev: 3.0 speed: 5 Gb/s
    power: 896mA chip-ID: 152d:1561 class-ID: 0806 serial: <filter>
  Hub-3: 2-2:2 info: VIA Labs USB3.0 Hub ports: 4 rev: 3.1 speed: 5 Gb/s
    chip-ID: 2109:0817 class-ID: 0900
  Hub-4: 2-3:3 info: Realtek Hub ports: 4 rev: 3.0 speed: 5 Gb/s
    chip-ID: 0bda:0411 class-ID: 0900
  Device-1: 2-3.1:4 info: JMicron / USA JMS561U two ports SATA 6Gb/s bridge
    type: Mass Storage driver: uas interfaces: 1 rev: 3.0 speed: 5 Gb/s
    power: 896mA chip-ID: 152d:1561 class-ID: 0806 serial: <filter>
  Device-2: 2-3.3:5 info: Realtek RTL8153 Gigabit Ethernet Adapter
    type: Network driver: r8152 interfaces: 1 rev: 3.0 speed: 5 Gb/s power: 288mA
    chip-ID: 0bda:8153 class-ID: 0000 serial: <filter>
  Hub-5: 3-0:1 info: Hi-speed hub with single TT ports: 12 rev: 2.0
    speed: 480 Mb/s chip-ID: 1d6b:0002 class-ID: 0900
  Hub-6: 3-3:2 info: VIA Labs USB2.0 Hub ports: 5 rev: 2.1 speed: 480 Mb/s
    chip-ID: 2109:2817 class-ID: 0900
  Device-1: 3-3.1:4 info: Holtek Optical Mouse type: Mouse
    driver: hid-generic,usbhid interfaces: 1 rev: 1.1 speed: 1.5 Mb/s
    power: 100mA chip-ID: 04d9:0499 class-ID: 0301
  Device-2: 3-3.2:7 info: Microsoft Natural Ergonomic Keyboard 4000 V1.0
    type: Keyboard,HID driver: microsoft,usbhid interfaces: 2 rev: 2.0
    speed: 1.5 Mb/s power: 100mA chip-ID: 045e:00db class-ID: 0300
  Device-3: 3-3.5:9 info: VIA Labs USB Billboard Device type: Billboard
    driver: N/A interfaces: 1 rev: 2.0 speed: 480 Mb/s power: 100mA
    chip-ID: 2109:8817 class-ID: 1100
  Hub-7: 3-4:3 info: Realtek RTS5411 Hub ports: 4 rev: 2.1 speed: 480 Mb/s
    chip-ID: 0bda:5411 class-ID: 0900
  Device-1: 3-4.4:6 info: Apple iPhone 5/5C/5S/6/SE type: Still Imaging
    driver: ipheth,usbfs interfaces: 3 rev: 2.0 speed: 480 Mb/s power: 500mA
    chip-ID: 05ac:12a8 class-ID: 0601 serial: <filter>
  Device-2: 3-9:5 info: Shenzhen Goodix USB2.0 MISC type: <vendor specific>
    driver: N/A interfaces: 1 rev: 2.0 speed: 12 Mb/s power: 100mA
    chip-ID: 27c6:609c class-ID: ef00 serial: <filter>
  Device-3: 3-10:8 info: Intel AX210 Bluetooth type: Bluetooth driver: btusb
    interfaces: 2 rev: 2.0 speed: 12 Mb/s power: 100mA chip-ID: 8087:0032
    class-ID: e001
  Hub-8: 4-0:1 info: Super-speed hub ports: 4 rev: 3.1 speed: 10 Gb/s
    chip-ID: 1d6b:0003 class-ID: 0900
Sensors:
  System Temperatures: cpu: 39.0 C mobo: N/A
  Fan Speeds (RPM): N/A
Info:
  Processes: 346 Uptime: 24m wakeups: 2 Init: systemd v: 252 default: graphical
  tool: systemctl Compilers: gcc: 12.2.1 clang: 15.0.7 Packages: pm: pacman
  pkgs: 1296 libs: 363 tools: pamac,yay pm: flatpak pkgs: 0 Shell: Zsh v: 5.9
  running-in: konsole inxi: 3.3.25