2.9.5 kept crashing on me the first time I opened it. It took multiple rounds of open, deal with error messages, crash, reopen before it finally got its pants on straight. Now it's running pretty well, though obviously still beta software.
It should have saved a copy of your pre-2.9.5 data in ~/Library/Application Support/openlp. Just rename the current "Data" folder to something else (or delete it), and rename the "Data-YYYYMMDD-HHMMSS" folder to "Data" so that the old version can find its old data.