Communication protocol mismatch!

[fernvenue]

Hi, I'm using Yubico Authenticator on Debian Trixie/Testing, and pcscd service is running, but Yubico Authenticator still say that pcscd is not running, and I found out that there are some error messages in pcscd service:

Nov 07 14:42:18 OptiPlex pcscd[25770]: 00002907 ../src/winscard_svc.c:404:ContextThread() Communication protocol mismatch!
Nov 07 14:42:18 OptiPlex pcscd[25770]: 00000005 ../src/winscard_svc.c:406:ContextThread() Client protocol is 4:4
Nov 07 14:42:18 OptiPlex pcscd[25770]: 00000001 ../src/winscard_svc.c:408:ContextThread() Server protocol is 4:5

What should I do to fix this? Any help will be much appreciated :)

[ldet]

Experiencing the same, using the flatpack from flathub on debian trixie. Downgrading pcscd and libpcsclite1 to version 2.2.3-1 worked for me. Had to build those packages from source though.

The minor protocol version increased, and the pcsc-lite protocol versions must match exactly between the version included in the flatpack and the host. The upstream developer has an Blog article about that issue: https://blog.apdu.fr/posts/2022/02/accessing-smart-cards-from-inside/

[joelpurra]

The community flatpak on flathub mentions this as a packaging issue. The flatpak workaround is to use the beta flatpak.

NOTE: This (community) flatpak currently works only with distros that use version of pcsc-lite below 2.3.0. For distros that use version 2.3.0 and above use beta version of this flatpak. DON'T report this to Yubico.

• https://flathub.org/apps/com.yubico.yubioath
• https://github.com/flathub/com.yubico.yubioath/issues/101

Also successfully used ykman in a toolbox on Fedora F41 Silverblue; see linked issue.