I am running Zdesktop 7.1.2 on Fedora 16 64bit. I tried to install the URL Zimlet. However it does not come up in the Zimlet list on the Preferences screen. I see this error in the log. Can someone help, please ?

com.zimbra.cs.object.ObjectHandlerException: error running ZimletHandler com_zimbra_url
at com.zimbra.cs.object.ObjectHandler.parse(ObjectHan dler.java:113)
at com.zimbra.cs.mime.MimeHandler.getObjects(MimeHand ler.java:278)
at com.zimbra.cs.mime.ParsedMessage.getMainBodyLucene Document(ParsedMessage.java:928)
at com.zimbra.cs.mime.ParsedMessage.analyzeNonBodyPar ts(ParsedMessage.java:428)
at com.zimbra.cs.mime.ParsedMessage.analyzeFully(Pars edMessage.java:454)
at com.zimbra.cs.mailbox.Mailbox.addMessage(Mailbox.j ava:4680)
at com.zimbra.cs.mailbox.InitialSync.saveMessage(Init ialSync.java:1294)
at com.zimbra.cs.mailbox.InitialSync.syncMessagesAsTg z(InitialSync.java:1095)
at com.zimbra.cs.mailbox.InitialSync.syncMessages(Ini tialSync.java:1010)
at com.zimbra.cs.mailbox.InitialSync.syncMessagelikeI tems(InitialSync.java:414)
at com.zimbra.cs.mailbox.DeltaSync.syncItems(DeltaSyn c.java:209)
at com.zimbra.cs.mailbox.DeltaSync.deltaSync(DeltaSyn c.java:158)
at com.zimbra.cs.mailbox.DeltaSync.sync(DeltaSync.jav a:95)
at com.zimbra.cs.mailbox.DeltaSync.sync(DeltaSync.jav a:78)
at com.zimbra.cs.mailbox.MailboxSync.sync(MailboxSync .java:190)
at com.zimbra.cs.mailbox.ZcsMailbox.sync(ZcsMailbox.j ava:121)
at com.zimbra.cs.mailbox.ZcsMailbox.syncOnTimer(ZcsMa ilbox.java:102)
at com.zimbra.cs.mailbox.SyncMailbox$1.run(SyncMailbo x.java:257)
at java.util.TimerThread.mainLoop(Timer.java:512)
at java.util.TimerThread.run(Timer.java:462)
Caused by: com.zimbra.cs.zimlet.ZimletException: null regex value
at com.zimbra.cs.zimlet.ZimletException.ZIMLET_HANDLE R_ERROR(ZimletException.java:34)
at com.zimbra.cs.zimlet.handler.RegexHandler.match(Re gexHandler.java:48)
at com.zimbra.cs.object.ObjectHandler.parse(ObjectHan dler.java:105)
... 19 more