Mobile App Designer mis-configuration error

I've been doing some work recently with OBIEE's new Mobile App Designer (MAD). It's a great bit of software that I'm genuinely impressed with, but it's got its little v1 quirks, and helpful error messages are not its forte. I hit a MADdening (sorry) problem with it that Google and My Oracle Support both drew blanks on, so I'm posting it here in case it helps out others with the same problem.

Setting up MAD is a bit of a fiddly process involving patching OBIEE (regardless of the base version you're on - hopefully in the future it will get rolled into the patchsets) and performing other bits of setup detailed in the documentation. The problem that I hit manifested itself twofold:

1. Publishing an App to the Apps Library worked fine, but updating an existing App threw an error in the browser:

   Failed to publish /~weblogic/GCBC Mobile - Phone.xma:oracle.xdo.webservice.exception.AccessDeniedException: PublicReportService::executeUpdateTemplateForReport Failure: user has no access to report[/Apps Library//GCBC Mobile - Phone.xma] due to [Ljava.lang.StackTraceElement;@4e6106df

2. Trying to subscribe to any App threw a generic error in the browser: "Error occurred while accessing server. Please contect administrator." with the corresponding bipublisher.log showing: 

   [2014-05-13T16:49:53.449+01:00] [bi_server1] [WARNING] [] [oracle.xdo] [tid: 24] [userId: <anonymous>] [ecid: 3f3d2d8955322f32:2f756afc:145f4d10b2f:-8000-0000000000003eea,0] [APP: bimad#11.1.1] User (weblogic) with session id: q2fq8fkh66f85ghamsq164u9qs98itvnk0c826i is looking for object in biee path: /shared/Apps Library//GCBC.xma/_mreport.xma[[
   Object Error [Context: 0, code: QM3V3HLV, message: Invalid path (/shared/Apps Library//GCBC.xma/_mreport.xma) -- ]
   ]]
   [2014-05-13T16:49:53.450+01:00] [bi_server1] [WARNING] [] [oracle.xdo] [tid: 24] [userId: <anonymous>] [ecid: 3f3d2d8955322f32:2f756afc:145f4d10b2f:-8000-0000000000003eea,0] [APP: bimad#11.1.1] oracle.xdo.XDOException: Target app not found in the repository :/Apps Library//GCBC.xma[[
       at oracle.xdo.online.AppStoreIO.doPost_subscribeApp(AppStoreIO.java:311)
       at oracle.xdo.online.AppStoreIO.doPost(AppStoreIO.java:120)
   [...]

One of my esteemed Rittman Mead colleagues, Francesco Tisiot, pointed out that the path referenced in the errors has a double slash in it. On checking my configuration, I had indeed fat-fingered one of the settings. APPS_LIBRARY_FOLDER_LOCAL is defined in the <DOMAIN_HOME>/config/bipublisher/repository/Admin/Configuration/xmlp-server-config.xml file, and mine looked like this:

<property name="APPS_LIBRARY_FOLDER_LOCAL" value="/Apps Library/"/>

All I needed to do was to remove the trailing slash after Library:

<property name="APPS_LIBRARY_FOLDER_LOCAL" value="/Apps Library"/>

After restarting the bimad application deployment all was good again with the MAD world and I could republish and subscribe to Apps happily.