Umbraco-cms: If Attribute Routing is enabled and a named route is used the backoffice breaks

[martina-1995]

If Attribute Routing is enabled

    public void OnApplicationStarted(UmbracoApplicationBase umbracoApplication, ApplicationContext applicationContext)
    {
    GlobalConfiguration.Configuration.MapHttpAttributeRoutes();
    }

And a named route is used (webapi)
[Route("votephoto", Name = "votephotoroute")]

The backoffice breaks with:
" System.ArgumentException: A route named 'votephotoroute' is already in the route collection. Route names must be unique.
Parameter name: name "

I've tried different names and deleted the bin/obj (just in case) but without success.
The only fix was to remove the Named Route and use an hardcoded link in the chstml.
I've asked on slack for this problem and the good Mads Krohn advised me to open an issue as it's a known bug.

Umbraco version: 7.11.1

[zpqrtbnk]

See https://github.com/umbraco/Umbraco-CMS/issues/4464 ?

[zpqrtbnk]

Ah - that's a v8 issue, and looks like the same thing happens on v7?

[martina-1995]

Ah - that's a v8 issue, and looks like the same thing happens on v7?

Yes Stephan I'm having the problem on v7

[CodeCheetah]

Yes, same problem using v7.14.0

[Matthew-Wise]

Will this get fixed for 7.15?

[Myster]

still broken in 7.15.1

[angelomiguelsantos]

Hello still broken in 7.15.3 ...any news on this ...anyone solved this question ?

thank you

Angelo