Sorry to hear about your troubles with the Zymurgy app. We are always striving to continually improve the app experience.
We do hear of the 'document error' from time to time, usually because an issue didn't complete downloading or was interrupted. You can tap and hold the issue to delete, then try again. If the problem persists, please let us know which issue is causing the problem.
re: disappearing issues, we have not been able to get that bug to repeat but I will add it to our bug list for further investigation. I assume you are able to re-download those missing issues?
Sr. Web Developer