0 A.D. Crashes on Multiplayer

[luchiz]

Hey everyone

0 A.D. just crashed when I tried to host a multiplayer session with a friend. I got this error in my log right after I clicked the start game button:

 

GAME STARTED, ALL INIT COMPLETE
/usr/include/c++/15.1.1/array:210: constexpr std::array<_Tp, _Nm>::value_type& std::array<_Tp, _Nm>::operator[](size_type) [with _Tp = std::pair<unsigned int, unsigned int>; long unsigned int _Nm = 2; reference = std::pair<unsigned int, unsigned int>&; size_type = long unsigned int]: Assertion '__n < this->size()' failed.
/usr/bin/0ad: line 9: 38514 Aborted                 (core dumped) "$pyrogenesis" "$@"

To reproduce:

• Go to Multiplayer > Host New Game
• Click Continue
• Wait for another player to join the game
• Click "Start Game"

I don't know if it's a bug in the Arch Linux official build or if it's really 0AD's source code. I tried hosting a multiplayer server without the other player and the problem persists.

Edited June 6, 2025 by luchiz
Grammar and clarity

[Stan`]

Hey yeah this is a bug that will be fixed in the next patch release. Sorry for the inconvenience. In the meantime you should be able to switch to Vulkan in the game option

[luchiz]

I'll try switching to Vulkan once I come back home. If it still doesn't work then it could be a bug in the engine itself and not the rendering stack.

Edited June 7, 2025 by luchiz
Grammar

[Stan`]

1 hour ago, luchiz said:

I'll try switching to Vulkan once I'll come back home. If it still doesn't work then it could be a bug in the engine itself and not the rendering stack.

No no, it's a known bug with OpenGL. IIRC the patch has been backported in the flatpak. It will also be in A27.1 which hasn't yet come out.

[luchiz]

Well apparently if people claim that Vulkan is faster than any Linux rendering API (which it clearly is) then I'll try switching to that. Also thanks a lot for the info

EDIT: It works! I changed from OpenGL to Vulkan and things seem to be great. The game loaded and I got to play with the friend I told you about in the OP. Thanks a lot!

Edited June 7, 2025 by luchiz