I have a simple test ics file at https://www.generomobile.de/gmi/cal.ics, and in Mobile Safari I get immediately the import dialog to add the test event to my calendar.
Using SFSafariViewController with
SFSafariViewController* sfvc=[[SFSafariViewController alloc] initWithURL:
leaves the page blank.
I have checked with .pdf URLs that the SFSafariViewController works, so can somebody enlighten me what is the secret with .ics files ?
I checked also with WKWebView ,nope , UIWebView was already discussed to be known not working for the .ics extension.