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Koen225142565mmt
Participant
January 5, 2022
Answered

Niet)ondersteund algoritme - Unsupported algoritme

  • January 5, 2022
  • 3 replies
  • 3905 views

I have a new (Belgian) eID. But the certificates were not longer recognised. So I re-Installed Adobe Acrobat Reader DC. The certificate for signature is now accepted and tested (5 green check marks). But at the end of the process to sign a .pdf document the error appears: (dutch:) “Fout aangetroffen tijdens ondertekenen: Niet-ondersteund algoritme” (free translated:)”Error encountered while signing: Unsupported algorithm”. What can I do? Please answer.

    Correct answer Koen225142565mmt

    The problem is solved. Solution : configure Acrobat Reader without pkcs#11 module.
    If this module has already been linked, the already linked module must therefore be uncoupled again.
    After unlinking, restart Acrobat Reader and try signing again.
    BELGIUM uses software called eID middleware that communicates with the card for Windows. In the past Acrobat Reader could not use this middleware and Acrobat Reader needed the pkcs11 module to do the communication with the card. Recently, ADOBE has made the necessary changes so that READER can work with the middleware.
    The pkcs11 module has now basically become optional within Acrobat Reader.

    3 replies

    K
    Koen225142565mmtAuthorCorrect answer
    Participant
    February 1, 2022

    The problem is solved. Solution : configure Acrobat Reader without pkcs#11 module.
    If this module has already been linked, the already linked module must therefore be uncoupled again.
    After unlinking, restart Acrobat Reader and try signing again.
    BELGIUM uses software called eID middleware that communicates with the card for Windows. In the past Acrobat Reader could not use this middleware and Acrobat Reader needed the pkcs11 module to do the communication with the card. Recently, ADOBE has made the necessary changes so that READER can work with the middleware.
    The pkcs11 module has now basically become optional within Acrobat Reader.

      M
      mathias_4680
      Participant
      August 12, 2025

      After removing the pkcs11 module there is no certificate shown to use to sign? Or am I missing something? I'm on MacOS 15.6.

      AnandSri
      Community Manager
      AnandSriCommunity Manager
      Community Manager
      November 12, 2025

      Hi, the problem still persists on macOS 26.0.1. Everything goes as is supposed to, even creates for a second the signature on the file, but then the same message “Error encountered while signing: Unsupported algorithm”  and the signature dissapears. I have the latest build 25.001.20841. So we have to wait for a new version of Acrobat for macOS? Any idea how long?


      Hello @andrei_b1983

       

      I hope you are doing well. The team is working on a fix, and once it is available with the public build, we will share an update here. Thanks for your time and cooperation on this.

       

      Regards,

      Anand Sri.

        try67
        Community Expert
        try67Community Expert
        Community Expert
        January 24, 2022

        Contact the authority that issued this signature profile and ask for exact instructions on how to use it.

        It's also recommended to go to the application's Preferences (via the Edit menu on Windows or the Reader app menu on a Mac), then to Trust Manager and click both Update Now buttons there.

        S
        Senne22794518b6zp
        Participant
        January 23, 2022

        I'm having the same issue, Did you find a solution yet?

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