This belongs in bug reports, but ...

What ZC version are you using?
With that icon, you completed 1st.qst, and are now on 2nd.qst in the same save slot. Is that correct, or are you on 3rd/4th/5th?

Replicating this bug might be a problem, really, but it would be good to know what version you are using. It clearly should not happen.

Upload your zc.sav file somewhere, and PM a link to it to me, so that I can check it in a few ZC builds, and see if I have the same problem with it that you have.