>first time using Encore since I installed Mavericks,
Go to http://forums.adobe.com/community/premiere and, in the area just under Ask a Question, type in
mavericks
You may now read all the previous discussions on this subject... be sure to click the See More Results at the bottom of the initial, short list if the initial list does not answer your question
Do the same for http://forums.adobe.com/community/encore to see discussions specific to Encore
I am Windows so did not bookmark the messages, but I have seen SOME message threads with SOME solutions for SOME mavericks problems