I just updated my Mac to High Sierra 10.13.1 and now I can't preview my Captivate projects in HTML5 or publish them. What can I do? Thanks for your help

Adobe has the fix.  You must uninstall Captivate 2017 and download the Mac 10.13.1 friendly version. I tried to insert the link or paste here, no go, sorry.  If you contact support they send you a link to DropBox, from there you can download.

Works like a charm.

-CJ

Bit too late, but if you had searched in this forum you would have seen that Captivate is not compatible with High Sierra at this moment. You'll have to wait for a patch. Apple never cares about other applications, not only Captivate suffers from that, quite a lot of the big Adobe applications had problems as well.