Server Error in '/' Application.
The resource cannot be found.
Description: HTTP 404. The resource you are looking for (or one of its dependencies) could have been removed, had its name changed, or is temporarily unavailable. Please review the following URL and make sure that it is spelled correctly. Requested URL: /xxxx/sitename/listname/forms/AllItems.aspx
This was strange, since the library was successfully created, and you could navigate to the library with SP Designer or with Site Settings -> Content and Structure. Looking into the ULS Logs showed that the site was configured to use a master page that did not exist anymore, e.g.
10/16/2009 11:25:00.34 w3wp.exe (0x10B0) 0x1920 Windows SharePoint Services General 8nca Verbose Application error when access /sites/sitename/listname/Forms/AllItems.aspx, Error=The file /sites/sitename/sitename/sitename/sitename/_catalogs/masterpage/default.master does not exist. at Microsoft.SharePoint.ApplicationRuntime.SPRequestModuleData.GetWebPartPageData(HttpContext context, String path, Boolean throwIfFileNotFound) at Microsoft.SharePoint.ApplicationRuntime.SPVirtualFile.CalculateFileDependencies(HttpContext context, SPRequestModuleData basicRequestData, ICollection& directDependencies, ICollection& childDependencies) at Microsoft.SharePoint.ApplicationRuntime.SPDatabaseFile.EnsureDependencies(HttpContext context, SPRequestModuleData requestData) at Microsoft.SharePoint.ApplicationRuntime.SPDatabaseFile.EnsureCacheKeyAndViewStateHash(HttpContext context, SPRequestModuleData re...
Navigate to Site Settings -> Master Page, will reveal the error as well, e.g.
The system master page setting currently applied to this site is invalid. Please select a new master page and apply it.
Fixed easily enough by choosing a valid master page.