Owin Error on first launch after installing site for umbraco 7 clients

Question

I get this error when building 7.3 umbraco:

The following errors occurred while trying to download the application. - The value of OwinStartupAttribute.FriendlyName 'UmbracoDefaultOwinStartup' does not match the set value '' in Assembly 'umbraco, Version = 1.0.5750.18164, Culture = neutral, PublicKeyToken = zero. - The assembly was not found using Startup or [AssemblyName]. Class startup. To disable OWIN startup detection, add appSetting owin: AutomaticAppStartup with the value "false" in your web.config. To specify a run in an OWIN Assembly, Class, or Method, add appSetting owin: AppStartup with the full qualification of the run class or the name of the configuration method in the web.config file.

Any ideas? I even deleted owin.dll from the bin folder and the link from the solution, also added to web.config <add key="owin:AutomaticAppStartup" value="false" />and still getting the same error?

thanks

Answer 1

If you enter the following web.config appSettings settings, it should spring to life:

<add key="owin:AutomaticAppStartup" value="true" />
<add key="owin:appStartup" value="UmbracoDefaultOwinStartup" />

I got this error after updating 7.2.8 → 7.4.1. After doing the above, Umbraco stated that it could not find System.Object. This was allowed by adding the following section to the assembly:

<add assembly="System.Runtime, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" />

; - ( , "umbraco" Microsoft.Owin 2.1.0, Umbraco NuGet 3.0.1.0), assemblyBinding:

<dependentAssembly>
   <assemblyIdentity name="Microsoft.Owin" publicKeyToken="31bf3856ad364e35" culture="neutral" />
   <bindingRedirect oldVersion="0.0.0.0-3.0.1.0" newVersion="3.0.1.0" />
</dependentAssembly>
<dependentAssembly>
    <assemblyIdentity name="Microsoft.Owin.Security.OAuth" publicKeyToken="31bf3856ad364e35" culture="neutral" />
    <bindingRedirect oldVersion="0.0.0.0-3.0.1.0" newVersion="3.0.1.0" />
</dependentAssembly>
<dependentAssembly>
   <assemblyIdentity name="Microsoft.Owin.Security" publicKeyToken="31bf3856ad364e35" culture="neutral" />
   <bindingRedirect oldVersion="0.0.0.0-3.0.1.0" newVersion="3.0.1.0" />
</dependentAssembly>
<dependentAssembly>
   <assemblyIdentity name="Microsoft.Owin.Security.Cookies" publicKeyToken="31bf3856ad364e35" culture="neutral" />
   <bindingRedirect oldVersion="0.0.0.0-3.0.1.0" newVersion="3.0.1.0" />
</dependentAssembly>