Folder Redirection Breaks WebView2 when File Server shares are not accessible

Hi Everyone- working in an enterprise environment and implementing Cisco Secure Client which uses WebView2 for SAML sign in. For months we have been battling an issue where WebView2 hangs for about 1-2 mins when it launches. This leads to extreme delays in users signing into the VPN. After many calls with Cisco, and a lot of digging, we have found that WebView2 tries to access the current users desktop, which in our case, is redirected to a file server DFS share, that is not yet accessible because the users are not logged into the VPN yet. You can use ProcMon to watch WebView2 as it queries the registry for the users desktop path(in our case, a non-accessible DFS share), tries to access that path, and then times out.

This is a major deal brakers for vendors to implement SAML auth for VPN with WebView2 because, by nature, anyone using folder redirection does not have desktop access until the VPN is established.

Wireshark showing enumeration of Desktop SMB shares (I made the shares available to the client machine pre-login to demonstrate this issue):

ProcMon of WebView2 Process accessing Desktop (once again, I artificially allowed this to succeed, but normally it would fail causing a WebView2 white screen until the timeout):

And finally, the user-facing symptom we are blessed with:

As more organizations move to SAML sign in for VPN login, I believe this will become an issue that more organizations experience, pinpointing this issue alone took hours of my time, along with many people from Cisco TAC.

AB#48035763