We have been encountering more and more frequently the Visual Studio error of being unable to generate the designer file in a web project. This problem has been occurring for a few months now, in several of our ASP.NET projects.
The errors occur when saving a file or when building the project, and are variations of errors like this:
- Generation of the designer file for [filename] failed: Error HRESULT E_FAIL has been returned from a call to a COM component.
- Generation of the designer file for [filename] failed: Unspecified error (Exception from HRESULT: 0x80004005 (E_FAIL))
- Generation of the designer file for [filename] failed: An entry with the same key already exists.
- Generation of the designer file for [filename] failed: Value cannot be null.
Sometimes, additional error messages are displayed for valid, previously-working code/markup; errors such as:
- The name 'Eval' does not exist in the current context
This is with Visual Studio 2013 (Premium), with "Web Application Projects" type projects using the .NET 4.5 framework. Some of the projects were originally created in Visual Studio 2010 or Visual Studio 2012, but one of the projects was a new project created in Visual Studio 2013.
We have a few Visual Studio extensions installed, such as "Web Essentials 2013", but I have tried disabling all the installed Visual Studio extensions and the same designer file errors still occur. We do not have Resharper or CodeRush installed. We are also using a third-party components package (DevExpress) for ASP.NET. We are using IIS Express for the local development web server.
All available updates (including Update 1 for Visual Studio 2013) have been installed for Visual Studio, the operating system (Windows 8.1), .NET, Visual Studio extensions, and DevExpress.
I have searched StackOverflow and the web for this issue, and have found some suggestions but no solutions, and I have also seen that the issue has been reported to Microsoft several times, dating back some years.
Many indications are that the problem with generating designer files is caused by some invalid syntax (in an ASPX file), or multiple elements with the same ID in the same scope, or collisions in namespace or class names, etc. I have searched through our projects as best as I can for issues like this, but haven't found any.
I found the Redesigner project on Sourceforge (thanks very much to the author), and I tried using that to verify the designer files, but unfortunately it can't handle the DevExpress components (it reports that DevExpress elements are using invalid child tags when the tags are valid and correct for DevExpress).
I have also tried clearing the Visual Studio development cache on my workstation (that is, deleting everything from the folders "\Temp\IISExpress", "\Temp\Temporary ASP.NET Files", and "\Microsoft\WebsiteCache" folders in the %localappdata% folder, rebooting and restarting Visual Studio.
I also found a website that explained how to turn on additional logging for Visual Studio to help with tracking down designer file generation issues. For Visual Studio 2013, this requires adding a key HKEY_CURRENT_USER\Software\Microsoft\VisualStudio\12.0\WebApplicationProjects\Debug and then adding values under that key for "Enabled" (set to 1), "LogFieldGeneratorFailures" (set to 1), and "LogFile" (set to a path and filename that you have permission to write to).
When I added this key, Visual Studio 2013 did write to the debug log file, but it only included error messages similar to the error messages above plus a small stack trace plus the entire content of the ASPX file for which the designer file could not be generated (with no apparent indication of where in the ASPX page there might be an error or invalid syntax).
I think I have tried essentially all suggested approaches in this topic: How do you force Visual Studio to regenerate the .designer files for aspx/ascx files?
None of these have worked for me. The "Convert to Web Application" option for the ASPX file is not available for me in Visual Studio 2013 in these projects.
Does anyone have any suggestions for potential causes or fixes for this desinger file issue or for any other troubleshooting approaches?