Versions definitely affected:

• 6.2.1
• 7.1.4

Using Net 4.5 on Windows 7.

I stumbled upon this whilst testing the next version of ImageProcessor with Umbraco.

Testing with a clean install of 7.1.4 using the default starter kit and passing the querystring params

?format=bmp

?format=webp

I get the following exception.

[InvalidOperationException: The UmbracoContext.Current is null, ProcessRequest cannot proceed unless there is a current UmbracoContext]
   Umbraco.Web.UmbracoModule.ProcessRequest(HttpContextBase httpContext) +189
   Umbraco.Web.UmbracoModule.<Init>b__a(Object sender, EventArgs e) +132
   System.Web.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +136
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +69

I'm also getting it using v6.2.1 without any starter kits.

Testing ImageProcessor outwith Umbraco runs perfectly with all formats working

That's all it's giving me I'm afraid. All other format extensions (jpg, gif, png, png8) work.

Removing RAMMFAR from theweb.config does not seem to make any difference also.

Update

It's definitely something in the UmbracoModule. If I add preCondition="managedHandler" to the declaration in the web.config then the error disappears.