When the shared persistence shared folder path contains double backslashes(\\), import of Apps with App content will fail.
During the installation, the path specified for Shared Persistence should be for example \\Machinename\share
If the path was specified to \\Machinename\share\ (with a final backslash), it will cause subfolder paths to contain double backslashes
For example: \\QLIKSERVER3\Share\\StaticContent
This does not cause any issue in most of features in Qlik Sense, but for the app import, it will prevent apps containing app contents to be imported.
The solution to this is to modify the cluster settings using the diagnostic tool (recommended, available from the September 2017 release)
In other release, you will need to make the necessary changes in the "ServiceClusterSettingsSharedPersistenceProperties" table in the repository following the steps below:
1) Stop all services except the Repository Database service.
2) Open the command line as an administrator:
cd "C:\Program Files\Qlik\Sense\Repository\PostgreSQL\9.6\bin"
psql -U postgres -p 4432
(You will be asked to input the password for the repository)
UPDATE "ServiceClusterSettingsSharedPersistenceProperties" SET "RootFolder" = '\\QLIKSERVER3\Share', "AppFolder"=\\QLIKSERVER3\Share\Apps',"StaticContentRootFolder"='\\QLIKSERVER3\Share\StaticContent', "Connector32RootFolder"='\\QLIKSERVER3\Share\CustomData',"Connector64RootFolder"='\\QLIKSERVER3\Share\CustomData', "ArchivedLogsRootFolder"='\\QLIKSERVER3\Share\ArchivedLogs';
(In this case \\QLIKSERVER\Share is the name of the share you are using)
3) Start all Qlik Services