Crash: 'main' thread panic on app start [Flatpak]

[Y0shioSato]

Please confirm the following.

• I checked the existing issues for duplicate problems
• I have tried resolving the issue using the support portal
• I have ensured my Modrinth App installation is up to date

What version of the Modrinth App are you using?

0.15.8

What operating systems are you seeing the problem on?

Linux

Describe the bug

Crash on launching the app

Steps to reproduce

1. Launch the app
2. Profit? Crash

Expected behavior

No response

Additional context

OS: openSUSE Tumbleweed x86_64 
Kernel: 7.1.2-1-default 
DE: Plasma 6.7.2 [KF 6.27.0] [Qt 6.11.1] (wayland)
GPU: AMD ATI Radeon RX 7900 XT/7900 XTX/7900 GRE/7900M

core.modrinth-app-wr.1000.9be31e52832840d5b28adc36aac46afe.59714.1783586660000000.tar.gz

flatpak run --branch=stable --arch=x86_64 --env=RUST_BACKTRACE=full --command=modrinth-app com.modrinth.ModrinthApp

thread 'main' (2) panicked at /home/runner/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tao-0.34.5/src/platform_impl/linux/event_loop.rs:218:53:
Failed to initialize gtk backend!: BoolError { message: "Failed to initialize GTK", filename: "/home/runner/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/gtk-0.18.2/src/rt.rs", function: "gtk::rt::init", line: 141 }
stack backtrace:
   0:     0x5606dc428a69 - <unknown>
   1:     0x5606dc110e04 - <unknown>
   2:     0x5606dc428101 - <unknown>
   3:     0x5606dc427e08 - <unknown>
   4:     0x5606dc44df97 - <unknown>
   5:     0x5606dc44df49 - <unknown>
   6:     0x5606dc44e43c - <unknown>
   7:     0x5606dc110c9b - <unknown>
   8:     0x5606dc1160a1 - <unknown>
   9:     0x5606dcdb9e97 - <unknown>
  10:     0x5606dce74baf - <unknown>
  11:     0x5606dcddd7e1 - <unknown>
  12:     0x5606dce900f9 - <unknown>
  13:     0x7fcb1fe2c975 - <unknown>
  14:     0x7fcb1fe2ca28 - __libc_start_main
  15:     0x5606dc041165 - <unknown>
  16:                0x0 - <unknown>

Hint: You are currently not seeing messages from other users and the system.
      Users in the 'systemd-journal' group can see all messages. Pass -q to
      turn off this notice.
           PID: 59714 (modrinth-app-wr)
           UID: 1000 (username)
           GID: 1000 (username)
        Signal: 6 (ABRT)
     Timestamp: Thu 2026-07-09 10:44:20 CEST (3s ago)
  Command Line: /app/bin/modrinth-app-wrapped
    Executable: /app/bin/modrinth-app-wrapped
 Control Group: /user.slice/user-1000.slice/user@1000.service/app.slice/app-flatpak-com.modrinth.ModrinthApp-1982956181.scope
          Unit: user@1000.service
     User Unit: app-flatpak-com.modrinth.ModrinthApp-1982956181.scope
         Slice: user-1000.slice
     Owner UID: 1000 (username)
       Boot ID: 9be31e52832840d5b28adc36aac46afe
    Machine ID: c8eaeaf39edb41c29d0b448f46b94255
      Hostname: localhost.localdomain
       Storage: /var/lib/systemd/coredump/core.modrinth-app-wr.1000.9be31e52832840d5b28adc36aac46afe.59714.1783586660000000.zst (present)
  Size on Disk: 1.8M
       Message: Process 59714 (modrinth-app-wr) of user 1000 dumped core.
                
                Module /usr/lib/x86_64-linux-gnu/libglycin-2.so.0 without build-id.
                Module /usr/lib/x86_64-linux-gnu/libglycin-2.so.0
                Module /usr/lib/x86_64-linux-gnu/libjavascriptcoregtk-4.1.so.0.10.12 without build-id.
                Module /usr/lib/x86_64-linux-gnu/libjavascriptcoregtk-4.1.so.0.10.12
                Module /usr/lib/x86_64-linux-gnu/libwebkit2gtk-4.1.so.0.21.8 without build-id.
                Module /usr/lib/x86_64-linux-gnu/libwebkit2gtk-4.1.so.0.21.8
                Stack trace of thread 2:
                #0  0x00007fcb1fe9d51c n/a (/usr/lib/x86_64-linux-gnu/libc.so.6 + 0x9c51c)
                #1  0x00007fcb1fe433be n/a (/usr/lib/x86_64-linux-gnu/libc.so.6 + 0x423be)
                #2  0x00007fcb1fe2a8ed n/a (/usr/lib/x86_64-linux-gnu/libc.so.6 + 0x298ed)
                #3  0x00005606dc44d63a n/a (n/a + 0x0)
                #4  0x00005606dc428189 n/a (n/a + 0x0)
                #5  0x00005606dc44e419 n/a (n/a + 0x0)
                #6  0x00005606dc238879 n/a (n/a + 0x0)
                #7  0x00005606dc4281c9 n/a (n/a + 0x0)
                #8  0x00005606dc427c8f n/a (n/a + 0x0)
                #9  0x00005606dc44df97 n/a (n/a + 0x0)
                #10 0x00005606dc44df49 n/a (n/a + 0x0)
                #11 0x00005606dc44e43c n/a (n/a + 0x0)
                #12 0x00005606dc110c9b n/a (n/a + 0x0)
                #13 0x00005606dc1160a1 n/a (n/a + 0x0)
                #14 0x00005606dcdb9e97 n/a (n/a + 0x0)
                #15 0x00005606dce74baf n/a (n/a + 0x0)
                ELF object binary architecture: AMD x86-64

[Y0shioSato]

Fixed by allowing app access to Wayland from the Flatpak sandbox

[Y0shioSato]

Better allow X11, with just Wayland Minecraft doesn't start.