Our webapp utilizes AppCache in order for users to use the app offline.
Recently we have encountered an intermittent issue on iOS devices running iOS 10. Occasionally when downloading the app to an iOS 10 device for the first time, after all of the files in the manifest have been downloaded Safari and Chrome will both prompt the user for their permission to increase the local storage.
Normally, the user would accept and the app would finish caching. Now with iOS 10, tapping 'increase' causes Safari to crash and Chrome to endlessly loop.
At first we suspected that the storage quota was being hit, but after doing some investigating we've learned that this is not the case. This issue does not affect iOS 8.x.x or 9.x.x. This issue is also not consistent. Many devices running iOS 10 have not encountered this issue, but we have been able to replicate this behavior on at least 3 devices running different versions of iOS 10.
Have there been any changes to iOS 10 that would account for this behavior?
I recently ran into the same issue with one of our web apps.
What we found is that Safari displays the message about increasing local storage to 50mb when the total file size being downloaded by the manifest exceeds 25MB.
Until Apple fixes the bug in iOS 10, it looks like web apps will have to keep their cache size to under 25 MB.
