How to reproduce:
You need a public key with two UIDs: one valid and one revoked UID.
When importing that key and trying to immediately certify it when prompted by the import dialog window, the certification results in a general error.
Certifying it after the import from the context menu works, though.
Debugview output is short, this is from the OK to the question if you want to certify now until the error occurs:
499 3866.983050 7548 kleopatra.exe org.kde.pim.kleopatra: handleOwnerTrust Skipping non-OpenPGP import 500 3875.423807 7548 kleopatra.exe org.kde.pim.kleopatra: Checked user IDs: std::vector("Jane Tester") 501 3875.424121 7548 kleopatra.exe org.kde.pim.kleopatra: Checked user IDs: std::vector("Jane Tester") 502 3886.348538 7548 kleopatra.exe org.kde.pim.kleopatra: Checked user IDs: std::vector("Jane Tester") 503 3886.353979 7548 kleopatra.exe org.kde.pim.kleopatra: Checked user IDs: std::vector("Jane Tester")
GPGMEPP_INTERACTOR_DEBUG: