Enterprise portal actually gave me this error related with SharePoint when trying to create EP from wizard.
An error occurred during setup of Enterprise Portal (EP) at http://win-ofm8ipk2leq/sites/Portal The following error/warning occurred:Setup encountered an error during deployment of the Role Center and Enterprise Portal framework. Entering method deployEPOnSharepoint Deploying Static files... C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\14\TEMPLATE\layouts\ep\images MergeNestedMasterPages:Success DeployStaticFiles:Success Deploying Static files...Complete Deploying Web Controls... \Web\Web Files\Web Controls - success Deploying Web Controls...Complete Deploying All Web Parts... Updating web.config file ... Setup could not find the Web server configuration location. The Web server configuration has not been updated. Setup could not find the Web server configuration location. The Web server configuration has not been updated. The Web server configuration file name is null or invalid: . Updating web.config file ...Complete Deploying proxies... In SysEPDeployment::deployProxies... In SysEPDeployment::clrGetVirtualServerProxyDir... The directory is not valid.