In contrast to gnupg22 master did not proper show OCB compliance - not everything has yet been forward ported. But we can do so now and test master by setting GNUPG_ASSUME_COMPLIANCE=de-vs

Notes for testing (and maybe documentation update):

• A few features (?) of the old CSR creation have been removed:
  • The different choices offered after CSR creation (e.g. save to file, send to CA, create signing/encryption CSR with same settings, etc.) have been removed; now a file save dialog pops up when the CSR has been generated
  • Custom labels for the RSA key sizes ([CertificateCreationWizard]RSAKeySizeLabels); we use GnuPG's algorithm IDs as labels (items in the drop down box)
  • Custom key type ([CertificateCreationWizard]CMSKeyType); CSR creation supported (and still supports) only RSA as "key type"; by marking the config key as immutable one could force the creation of signing+encryption CSRs which makes little sense for S/MIME and might have been "copied" from OpenPGP key creation where forcing the generation of keys for signing & encryption does make some sense.
  • Specification of the CA's email address ([CertificateCreationWizard]CAEmailAddress); the generated CSRs are now always written to disk; the users will have to create an email themselves

We will do a new gpg4win beta soon.

@m.eik Could you please enable debug option for gpg-agent and get the log output for the crash?

I fixed the problem (which I identified above) in gniibe/t7759 branch. There might be other causes/problems for the particular symptom, so, I don't know the fix resolves the symptom or not.