Having lots of problems with calendar sync since last Zimbra software update. Here's the error report
Debug message: Expected [-3], read [-1] at line 1

Exception:

com.zimbra.common.service.ServiceException: parse error: Caught ParseException parsing calendar: net.fortuna.ical4j.data.ParserException: Expected [-3], read [-1] at line 1

ExceptionId:btpool0-3:1236686004611:500cd5b13ea35ceb
Code:service.PARSE_ERROR
at com.zimbra.common.service.ServiceException.PARSE_E RROR(ServiceException.java:271)
at com.zimbra.cs.mailbox.calendar.ZCalendar$ZCalendar Builder.parse(ZCalendar.java:1051)
at com.zimbra.cs.mailbox.calendar.ZCalendar$ZCalendar Builder.buildMulti(ZCalendar.java:1007)
at com.zimbra.cs.mailbox.calendar.ZCalendar$ZCalendar Builder.build(ZCalendar.java:991)
at com.zimbra.cs.datasource.CalDavDataImport.applyRem oteItem(CalDavDataImport.java:413)
at com.zimbra.cs.datasource.CalDavDataImport.sync(Cal DavDataImport.java:497)
at com.zimbra.cs.datasource.CalDavDataImport.importDa ta(CalDavDataImport.java:77)
at com.zimbra.cs.offline.OfflineCalDavDataImport.impo rtData(OfflineCalDavDataImport.java:53)
at com.zimbra.cs.offline.OfflineImport.importData(Off lineImport.java:88)
at com.zimbra.cs.offline.YMailImport.importData(YMail Import.java:56)
at com.zimbra.cs.datasource.DataSourceManager.importD ata(DataSourceManager.java:154)
at com.zimbra.cs.mailbox.LocalMailbox.importData(Loca lMailbox.java:417)
at com.zimbra.cs.mailbox.LocalMailbox.syncAllLocalDat aSources(LocalMailbox.java:389)
at com.zimbra.cs.mailbox.LocalMailbox.sync(LocalMailb ox.java:431)
at com.zimbra.cs.service.offline.OfflineSync.handle(O fflineSync.java:49)
at com.zimbra.soap.SoapEngine.dispatchRequest(SoapEng ine.java:429)
at com.zimbra.soap.SoapEngine.dispatch(SoapEngine.jav a:286)
at com.zimbra.soap.SoapEngine.dispatch(SoapEngine.jav a:160)
at com.zimbra.soap.SoapServlet.doPost(SoapServlet.jav a:269)
at javax.servlet.http.HttpServlet.service(HttpServlet .java:727)
at com.zimbra.cs.servlet.ZimbraServlet.service(Zimbra Servlet.java:190)
at javax.servlet.http.HttpServlet.service(HttpServlet .java:820)
at org.mortbay.jetty.servlet.ServletHolder.handle(Ser vletHolder.java:487)
at org.mortbay.jetty.servlet.ServletHandler.handle(Se rvletHandler.java:362)
at org.mortbay.jetty.security.SecurityHandler.handle( SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(Se ssionHandler.java:181)
at org.mortbay.jetty.handler.ContextHandler.handle(Co ntextHandler.java:716)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebA ppContext.java:406)
at org.mortbay.jetty.handler.ContextHandlerCollection .handle(ContextHandlerCollection.java:211)
at org.mortbay.jetty.handler.HandlerCollection.handle (HandlerCollection.java:114)
at org.mortbay.jetty.handler.HandlerWrapper.handle(Ha ndlerWrapper.java:139)
at org.mortbay.jetty.handler.RewriteHandler.handle(Re writeHandler.java:176)
at org.mortbay.jetty.handler.HandlerWrapper.handle(Ha ndlerWrapper.java:139)
at org.mortbay.jetty.Server.handle(Server.java:313)
at org.mortbay.jetty.HttpConnection.handleRequest(Htt pConnection.java:506)
at org.mortbay.jetty.HttpConnection$RequestHandler.co ntent(HttpConnection.java:844)
at org.mortbay.jetty.HttpParser.parseNext(HttpParser. java:644)
at org.mortbay.jetty.HttpParser.parseAvailable(HttpPa rser.java:211)
at org.mortbay.jetty.HttpConnection.handle(HttpConnec tion.java:381)
at org.mortbay.io.nio.SelectChannelEndPoint.run(Selec tChannelEndPoint.java:396)
at org.mortbay.thread.BoundedThreadPool$PoolThread.ru n(BoundedThreadPool.java:442)
Caused by: net.fortuna.ical4j.data.ParserException: Expected [-3], read [-1] at line 1
at net.fortuna.ical4j.data.CalendarParserImpl.assertT oken(CalendarParserImpl.java:395)
at net.fortuna.ical4j.data.CalendarParserImpl.assertT oken(CalendarParserImpl.java:435)
at net.fortuna.ical4j.data.CalendarParserImpl.parseCa lendarList(CalendarParserImpl.java:141)
at net.fortuna.ical4j.data.CalendarParserImpl.parse(C alendarParserImpl.java:100)
at com.zimbra.cs.mailbox.calendar.ZCalendar$ZCalendar Builder.parse(ZCalendar.java:1023)
... 39 more