I set up a web clip (.mobileconfig file) to open a served file from an iPad. When starting fresh with no open applications (over a VPN WAN connection) launching the clip results in an error message "Your access privileges do not allow you to perform this action."
Hit OK, and the file on the server then opens, and one can sign in with an account and all is fine.
The server is secure SSL DNS. iOS is configured with VPN (Fortigate).
Opening the target file on the server directly from the launch window within iOS does not give this error.
I tried creating the clip with Apple Configurator 2, signed and unsigned. I used App Maker, (which only allows unsigned). Happens in iOS 9 and 11.
Occasionally, the clip does not give this error (may have something to do the the sleep icon on FMP icon in the dock? Fresh clip?).
It's not a bug, it's a damnable gnat!