Is ASP.NET MVC 5 incompatible with the WebMatrix SimpleMembershipProvider?

WebMatrix is compatible with MVC 5.

What I did was to take an empty MVC 5 project and incorporate WebMatrix SimpleMembershipProvider into it using SimpleSecurity, an open source project that decouples SimpleMembership from your MVC application. So far I am able to create the database, seed it, and log in and out. I plan on adding other features to this reference application, such as email confirmation and various tests. When I am done I will post the source code in the SimpleSecurity Project

If I had to guess, your problem may be with the upgrade process. What process did you take to upgrade your MVC 4 project to MVC 5? Did you follow this process? What version of the WebMatrix assemblies are you using? What version of Visual Studio are you using? I am using version 2.0.0.0 of WebMatrix and Visual Studio 2013 RC.

Update (10/25/2013)

I continued my experiment with adding SimpleMembership to an MVC 5 project and somewhere along the line it broke and I got the same results as @Sixten Otto. I did not test incrementally as I added things but I am suspicious it may have happened when I installed the Web API assemblies. They are not installed by default when creating a new MVC 5 project.

I did some more research on the error and came across this QA titled "Attempt by security transparent method 'WebMatrix.WebData.PreApplicationStartCode.Start()'". This is an old QA and originally someone was getting this same error when upgrading an MVC 3 app to MVC 4. But recently people have been adding answers in regards to upgrading to MVC 5 and one of the answers worked for me. The solution for me was install the NuGet package Microsoft.AspNet.WebHelpers. After installing this package everything worked fine.

A note about my research into migrating to the new ASP.NET Identity is that they do not use the same password hash, which precludes moving old members into a database used by ASP.NET Identity. ASP.NET Identity seems to be in real flux right now so maybe they will come up with a solution for this.

Update (2/16/14)

I erroneously reported that the hash algorithm for passwords was different in SimpleMembership and ASP.NET Identity. I assumed this based on a visual inspection of the hashed passwords, assuming that it was just the hashed password that was in the fields. After further research I found that SimpleMembership uses the System.Web.Helpers.Crypto class for hashing the password and what is stored in the password field is actually a 256 bit subkey and the salt. With that information I ran some tests to validate that ASP.NET Identity can verify passwords that are generated by SimpleMembership, and it passed. I was trying to find out what hash algorithm SimpleMembership used so I could plug in a password hasher in ASP.NET Identity that would allow me to migrate data from a SimpleMembership webiste to one that used ASP.NET Identity. Turns out it is not necessary. I talk about the password hash and how to migrate the data from SimpleMembership to ASP.NET Identity in more detail in this article.

If you are getting the error

Attempt by security transparent method ‘WebMatrix.WebData.PreApplicationStartCode.Start()’ to access security critical method ‘System.Web.WebPages.Razor.WebPageRazorHost.AddGlobalImport(System.String)’ failed.

In order to fix this install this package using NuGet package manager.

Install-Package Microsoft.AspNet.WebHelpers

After that , probably you will get another error

Cannot load WebMatrix.Data version 3.0.0.0 assembly

to fix this install this package using NuGet package manager.

Install-Package Microsoft.AspNet.WebPages.Data