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Bug Crash in lib_burst_generated.dll on startup

Discussion in 'Burst' started by Plync, May 10, 2023.

  1. Plync

    Plync

    Joined:
    Aug 7, 2020
    Posts:
    17
    Updated from 2022.2.12 to 2022.2.18 and now whenever I launch the build version of the game, it crashes on startup. Shows the unity splashscreen then crashes.

    Windows 10 Version 19045
    .ecxr
    Unable to load image C:\Users\...\Plugins\x86_64\lib_burst_generated.dll, Win32 error 0n2
    *** WARNING: Unable to verify timestamp for lib_burst_generated.dll
    rax=000001d0734fef00 rbx=0000000000001400 rcx=000000bf5bfff300
    rdx=0000000000000000 rsi=0000000000000000 rdi=000001d110000000
    rip=00007ffb2ad81654 rsp=000000bf5bffed50 rbp=000000bf5bffee30
    r8=0000000000000000 r9=0000000000000000 r10=0000000000000000
    r11=000001d07350fa00 r12=000000bf5bfff300 r13=000001d180200300
    r14=000001d07335c9f0 r15=0000000000000001
    iopl=0 nv up ei pl nz na po nc
    cs=0033 ss=002b ds=002b es=002b fs=0053 gs=002b efl=00010206
    lib_burst_generated+0x1654:
    00007ffb`2ad81654 c5f829742440 vmovaps xmmword ptr [rsp+40h],xmm6 ss:000000bf`5bffed90=420fc950420d6500ffffffff00000000
     
    Last edited: May 11, 2023
    Plync, May 10, 2023
    #1

  2. tim_jones

    tim_jones

    Unity Technologies

    Joined:
    May 2, 2019
    Posts:
    287
    Hi @Plync - please could you log a bug report via Help > Report a Bug, with repro steps?
     
    tim_jones, May 11, 2023
    #2

  3. Plync

    Plync

    Joined:
    Aug 7, 2020
    Posts:
    17
    So a bit more info on this... It's ONLY happening on 1 of our test machines. An older Core i7 950, with a geforce 1080. I just gave it a full OS refresh to make sure its nothing machine related. Also upgraded unity to 2022.2.19 and still the same issue.

    Always the same error: Unhandled exception at 0x00007FFA2E5C1654 (lib_burst_generated.dll) in crash.dmp: 0xC000001D: Illegal Instruction.

    Update: If I DISABLE development build it works...
     
    Last edited: May 13, 2023
    Plync, May 13, 2023
    #3

  4. tim_jones

    tim_jones

    Unity Technologies

    Joined:
    May 2, 2019
    Posts:
    287
    Thanks @Plync - this looks very much like a bug that we've fixed in the upcoming Burst 1.8.5 (not yet released, but we plan to release it soon). The bug was that it was possible for AVX instructions to be incorrectly included in an SSE build, and since you mentioned that this only happens on an older Core i7 950, that sounds very related.

    For now, the workaround is to change your Burst AOT Settings, to build only for SSE and not anything newer (AVX etc).
     
    tim_jones, May 15, 2023
    #4