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Question How can I resolve this error? TypeError: Module.asm.$a is undefined

Discussion in 'Web' started by pbnggames, Aug 22, 2023.

  1. pbnggames


    Oct 14, 2019
    The webGL app I have deployed is not working and I can not figure out what is wrong. I updated the editor, I changed some settings according to a few videos I found but they were aimed at deployment on This is really frustrating me. I have deployed a webGL app in the past and did not have any issues. Any help would be greatly appreciated.

    This is the error code thrown by Firefox:

    Code (JavaScript):
    1. TypeError: Module.asm.$a is undefined
    2. unityFramework/Module.dynCall_viiiii@blob:
    3. invoke_viiiii@blob:
    4. @blob: line 10 > WebAssembly.instantiate:wasm-function[2589]:0x11b1c7
    5. @blob: line 10 > WebAssembly.instantiate:wasm-function[2589]:0x11aedc
    6. @blob: line 10 > WebAssembly.instantiate:wasm-function[26630]:0x1085431
    7. invoke_iii@blob:
    8. @blob: line 10 > WebAssembly.instantiate:wasm-function[1139]:0x80fba
    9. @blob: line 10 > WebAssembly.instantiate:wasm-function[26628]:0x108541b
    10. invoke_vi@blob:
    11. @blob: line 10 > WebAssembly.instantiate:wasm-function[54318]:0x16d56aa
    12. @blob: line 10 > WebAssembly.instantiate:wasm-function[54316]:0x16ca949
    13. unityFramework/Module._main@blob:
    14. callMain@blob:
    15. doRun@blob:
    16. run@blob:
    17. runCaller@blob:
    18. removeRunDependency@blob:
    19. unityFramework/</unityFileSystemInit</<@blob:
    20. doCallback@blob:
    21. done@blob:
    22. unityFramework/reconcile/transaction.oncomplete@blob:
    I can't find a way to copy and paste the error message thrown by Chrome. You can come to see the app yourself at
    Last edited: Aug 25, 2023
  2. CodeSmile


    Apr 10, 2014
    I assume Build&Run locally works fine?
    Try deploying to Unity Play via the WebGL Publisher asset from the store. Or to If that works, at least you know it‘s an issue with the webserver.
    Play with the build settings like compression. Be sure to deploy a debug build for testing.
    unityruba and pbnggames like this.
  3. pbnggames


    Oct 14, 2019
    Thank you for pointing me in the correct direction. The issue was that the server was not configured for web assembly files (/wasm) and this was resolved by adding a htaccess file to the game directory as described in the Unity manual here.
    unityruba likes this.