Somehow the Quest about Radovid, Sigi and Roche faild althoug I ended it. The quest was over but still in the log. After I headed to the last main quest I got a message that it failed. Also in the end summary, there were no mention about Geralt beeing involved in this.
That's not a "standard" failure, nor is it a generally-reported bug. Maybe you could follow-up on that in a different thread? Someone may be able to advise you on why it failed.