Error in WebDAV when code protected

2016-01-15 09:34:37,651 [ajp-nio-8009-exec-39] ERROR CoursefolderWebDAVNamedContainer - OLAT::ERROR ^% N1-E176797 ^% org.olat.course ^% hemsing
^% 131.246.246.153 ^% n/a ^% WebDrive 10.0.2521 DAV ^% Error loading course: org.olat.repository.RepositoryEntry@31998032 [resourcename=Testku
rs_D%E4hn.zip, version=793, description=<p>In diesem Kurs können Sie nur arbeiten, wenn Sie den Buchungscode kennen und im</p><p>Profil die Ma
trikelnummer eingetragen haben.</p>] ^% >>>stack of 1.cause::java.lang.NullPointerException: null -> at org.olat.course.MergedCourseContainer.add
FolderBuildingBlocks(MergedCourseContainer.java:186) at org.olat.course.MergedCourseContainer.addFolderBuildingBlocks(MergedCourseContainer.java:22
1) at org.olat.course.MergedCourseContainer.addFolderBuildingBlocks(MergedCourseContainer.java:221) at org.olat.course.MergedCourseContainer.init(M
ergedCourseContainer.java:125) at org.olat.course.PersistingCourseImpl.getCourseFolderContainer(PersistingCourseImpl.java:196) at org.olat.course.C
oursefolderWebDAVNamedContainer.getDelegate(CoursefolderWebDAVNamedContainer.java:58) at org.olat.core.util.vfs.NamedContainerImpl.exists(NamedCont
ainerImpl.java:58) at org.olat.core.commons.services.webdav.manager.VFSResource.exists(VFSResource.java:77) at org.olat.core.commons.services.webda
v.servlets.WebDAVDispatcherImpl.parseProperties(WebDAVDispatcherImpl.java:1987) at org.olat.core.commons.services.webdav.servlets.WebDAVDispatcherI
mpl.doPropfind(WebDAVDispatcherImpl.java:612) at org.olat.core.commons.services.webdav.servlets.WebDAVDispatcherImpl.webdavService(WebDAVDispatcher
Impl.java:306)