There may be a few reasons a device doesn't cache the Client Folio to your mobile device for offline viewing.

Make sure that the album is saved to the device home-screen with the preferred web-browser (Android - Chrome and Apple - Safari) and opened at least one time before trying to view offline. 

Note: When albums do not save offline there can be a variety of reasons.  When testing for offline make sure to put the device into Airplane mode. Some devices may still try to connect to WiFi even when none is available, which may not bring up the cached data.  

The best practice is to always make sure that the correct web-browser was used. 

1. Too many images included in the Client Folio.  

While you can load any number of images to Client Folio, mobile devices will only save a limited amount of data for offline viewing. 

Depending upon the number of images included in your Client Folio, you could reach the cache limit for your device.  To avoid this, we recommend using no more than your best 15-20 images in Client Folios. Or you can disable the Offline Caching in the Home screen Details Section if you wish to share a larger number of images.

2. The mobile device's settings don't allow offline caching.  

In some cases, users may have updated their device settings, which can prevent the Client Folio from saving for offline viewing. Typically, this happens when cookies are blocked.

Here are the recommended settings that will allow your app to cache on iOS devices using Safari:

Do Not Track:      Set to white (green means on, but you want it off)
Block Cookies:   Allow from Websites I Visit