When we configure Anonymous Authentication ,Spotfire Consumer/Business author users can open reports without logging into Web Player. Even after enabling ANONYMOUS Authentication it may still ask for credentials and you may see the following messages in server debug logs:
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DEBUG 2018-11-09T17:47:53,790-0700 [guestX@ANONYMOUS, #61, #33946] spotfire.rs.RestExceptionHandler: Resolving exception from handler [public org.springframework.web.servlet.ModelAndView com.spotfire.server.wp.controller.ViewAnalysisController.openAnalysis(javax.servlet.http.HttpServletRequest,javax.servlet.http.HttpServletResponse,com.spotfire.server.wp.domain.AnalysisOpenRequest,java.lang.String)]: com.spotfire.server.security.UnauthenticatedException
DEBUG 2018-11-09T17:47:53,790-0700 [guestX@ANONYMOUS, #61, #33946] server.security.SecurityFilter: The request is configured for the BASIC authentication method
DEBUG 2018-11-09T17:47:53,790-0700 [guestX@ANONYMOUS, #61, #33946] server.security.FormLoginUtil: Requesting client to authenticate using the FORM authentication scheme
DEBUG 2018-11-09T17:47:53,790-0700 [guestX@ANONYMOUS, #61, #33946] server.security.SessionUtil: Replacing old security context guestX@ANONYMOUS with new security context null
DEBUG 2018-11-09T17:47:53,790-0700 [guestX@ANONYMOUS, #61, #33946] server.security.InternalSecurityContext: Logged out user 'guest@ANONYMOUS[6679bcea-758d-4b72-8d50-32dfa6621239]'
DEBUG 2018-11-09T17:47:53,790-0700 [unknown, #61, #33946] server.security.SecurityFilter: Returning from filter after requesting the client to authenticate and without passing on the request to the next item in the filter chain
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• Configure anonymous authentication as described in the TIBCO Spotfire Server Administration Manual in the section titled “Configuring  anonymous authentication” (Refer the documentation URL provided in the KB)
• Grant the appropriate Spotfire Licenses to the special user guest@ANONYMOUS - either at the user-level or at the group-level
• Set the permissions on the Spotfire Library folder containing the Analysis File(s) to allow access to the guest@ANONYMOUS user
  • Note: Providing 'Everyone' access to the required library folders isn't sufficient. The user  'guest@ANONYMOUS' must be granted permissions explicitly to the folders needed.