During install of CF11, the Web Configuration Tool does not create a "CFML" handler in IIS 7.5 for the main web site. Specifics: 1. Uninstalled CF10. 2. Installed CF11. 3. Got websites functional. Default web page set to "index.cfm". 4. Found main page errors when no page specified. i.e. (https://www.xxx.yyy/) , Error: 404.5 Page not found, cfhandler error. 5. Several attempts of Web config Tool, once for specific web sites and then for ALL web sites. 6. Each attempt left the "CFML" handler out of the configuration for the main site. 7. Finally, running tool for "All", and then in main site "Handler Mappings", click on "Revert to Parent" pops in the missing handler and all works well. 8. Add corrective process to CF11 install procedures.
CF11 is on update 12, I'd start there is it's not fully updated.