Please see https://supportforums.cisco.com/t5/jabber-clients/jabber-login-issue/m-p/2022735#M2899
I have this same issue on a corporate PC. Jabber version version 11.8.3 Build 51659. Unable to sign in to Jabber - hangs up in "Signing in..." screen and pops up a file download message pointing to SAML2AuthService.xml file. Screen capture of the popup message is attached. The following fixes were attempted, but the problem still persists:
- Uninstalled/reinstalled Jabber
- Uninstalled/reinstalled WebEx productivity tools
- Reset Jabber
- Cleared Internet Explorer and Chrome caches and reset all browser settings to nominal
Screen capture of the error message is attached. Can provide additional information (logs, etc.) if needed. This error has the IT department stumped and they want to re-image my laptop. I would prefer to do something less drastic if there is a known fix for this.