Error when first opening app with iPhone

I deploy my app to my own ftp server.

When I first download my app in Safari I get the following popup message:

Update unsuccessful:
cache error

When I press “ok” the app runs normally.

Thereafter when I tap the app’s icon the app will update normally.

Why do I get this initial iOS error message? (I do not get any errors when I download to a Kindle)

Check out the first item in Tech Note 1:

Thank you. The soloution(s) worked.