Uploads from Android Filr app throws error when using Zen load balancer

When Filr is fronted with the Zen (or Zevenet) Load Balancer, android users see an error message when they try to upload one or more files into Filr. The error message displayed is:

Failed to upload file <filename>

However, if the user refreshes the folder, the file is actually uploaded. The error is not observed if the user bypasses the load balancer and connects directly to one of the Filr nodes in the cluster.

The problem is only observed when the Zen Load Balancer is configured as HTTP/S.

To fix the problem, re-configure the Zen Load Balancer and use a L4xNAT configuration instead of using the HTTP/S configuration. The steps involved are as follows:

1. Login to Zevent Load Balancer as admin.
2. Click on Manage > Farm, then create a new farm by clicking on '+' icon.
   
3. Specify a name for the farm in 'Farm Description Name' and ensure that Profile is selected as 'L4xNAT'.
   
4. Select the 'Virtual IP' which is the IP Address we want to expose to external users for connecting to Filr and specify the port number as '8443'.
5. Once the farm is created, it will be listed in the list of farms.
   
6. Click on the edit option to edit the farm settings, in order to add the Filr Server details.
7. Once inside the farm settings, specify the Filr server address by going to the sub-setting 'Edit real servers configuration' and click the '+' icon.
   
8. Add the Filr server IP address and port as 8443.
   The Weight and Priority is optional setting and can be ignored.
   
9. Click 'Save Real Server #' icon to finish creating the L4xNAT farm pointing to Filr server.
   

Zen Load Balancer was configured using the HTTP/S option which does not work.