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System.Security.Cryptography.X509Certificates error on appharbor. works in development

evilroxx's Avatar


28 Jul, 2017 01:58 AM

Why am I seeing this error when I deploy my app to appharbor?
Could not load file or assembly 'System.Security.Cryptography.X509Certificates' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)

1. I have also tried to change the configuration to debug and back to release however still persists.
2. works in dev
3. 4.6.1/2 .net framework...probably something to do with shitty Rosyln?

Any clue whats going on here? H.E.L.P...its kind of urgent! much appreciated

  1. 1 Posted by evilroxx on 28 Jul, 2017 02:40 AM

    evilroxx's Avatar had nothing to do with the error...Apparently its the Rosyln compiler BS that was causing the issue...after I followed this and re-deployed it started working...also btw the swagger issue I had was always fixed and its working now. I followed your exact steps. THANK YOU SO MUCH!!! You are the best, Rune.


  2. evilroxx closed this discussion on 28 Jul, 2017 02:40 AM.

  3. evilroxx re-opened this discussion on 29 Jul, 2017 07:32 PM

  4. 2 Posted by evilroxx on 29 Jul, 2017 08:38 PM

    evilroxx's Avatar

    After fixing the Roslyn issue....the DLL issue still persists...can you please suggest whats going on here? I am running out of ideas and time.

  5. 3 Posted by evilroxx on 29 Jul, 2017 10:58 PM

    evilroxx's Avatar

    So...if I remove the newVersion property or comment out the entire element from web.config then it works.
            <assemblyIdentity name="System.Security.Cryptography.X509Certificates" publicKeyToken="b03f5f7f11d50a3a" culture="neutral" />
            <bindingRedirect oldVersion="" newVersion="" />

    do you know what is going on here?

  6. Support Staff 4 Posted by rune on 02 Aug, 2017 02:37 AM

    rune's Avatar


    I took a look at the application's Errors page but there doesn't seem to be any recently unhandled exceptions. Where are you seeing this issue and is there a way I can reproduce it?


  7. 5 Posted by evilroxx on 25 Aug, 2017 04:15 AM

    evilroxx's Avatar

    It's happening during build...

  8. Support Staff 6 Posted by rune on 26 Aug, 2017 07:18 AM

    rune's Avatar


    Ok got it -- sounds like you've fixed another Roslyn related error, so can we close this one for now?


  9. 7 Posted by evilroxx on 07 Nov, 2017 02:41 AM

    evilroxx's Avatar

    yes please. thanks for all your help!

  10. Support Staff 8 Posted by rune on 07 Nov, 2017 04:41 AM

    rune's Avatar

    Ok great, thanks for the heads up! Let me know if there's anything else I can help with.


  11. rune closed this discussion on 07 Nov, 2017 04:41 AM.

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