A route named 'DefaultRoute' is already in the route collection. Route names must be unique

Question

When I publish an ASP.NET WebAPI solution to a remote IIS Server, I get the error message:

Message: System.ArgumentException: A route named 'DefaultRoute' is already in the route collection. Route names must be unique.

I saw this thread with the same problem, but nothing on it has worked. I have tried:

Deleting all bin/obj folders in all projects.
Cleaning/Rebuilding
Deleting files off the the remote server before publishing
Renaming the project

Is there anyway I can find out if there is a stale file. I did rename some files and I heard that this can cause a problem?

Not sure if this matters, but I am using the ASP.NET WebApi along with RestSharp to make my rest calls.

This is what my Global.asax startup has: Is it redundant?

AreaRegistration.RegisterAllAreas();
WebApiConfig.Register(GlobalConfiguration.Configuration);
RouteConfig.RegisterRoutes(RouteTable.Routes);

Search in you solution `RouteTable` and check whether do you map in its `Routes` collection more than one route with name 'Default'. — Hamlet Hakobyan, Jan 28 '15 at 15:04
Double check so that you don't do the route initialization in both global asax and in a OWIN startup class. — peco, Jan 28 '15 at 16:07

score 9 · Answer 1 · edited May 23 '17 at 11:53

9

I came to similar problem with already set routes. For me the solution was here: https://stackoverflow.com/a/28503674/1496138 . Problem was I later renamed project file - old DLL files with previous name still existed in the /bin directory and automatic startup configuration run them too.

edited May 23 '17 at 11:53

Community

1
1

answered Sep 23 '15 at 15:02

Kraken101

164
2
6

Yep - me too, renamed a project but the old .DLL existed still, once I deleted it the problem went away – Greg Trevellick Jun 28 '17 at 12:55
Same here. Switched between branches that had project namespace adjusted which resulted in the different dll. Cleaning it up helped. Thank you! – mike123 Jul 22 '17 at 00:37
Deleting the **bin** folder was enough (thanks for sharing the problem about the old dlls). – Alisson Reinaldo Silva Apr 03 '18 at 18:57

score 1 · Answer 2 · answered Jan 29 '15 at 23:21

Routes are usually configured one of three places. The global.asax file, the RouteConfig.cs file (usually found in /App_Start or in an {areaname}AreaRegistration.cs file which is found in /Areas/{areaname}. There must be a duplicate route name in these places. Since it is giving you the name that is duplicated, try searching for "DefaultRoute" in your project and it will probably jump out. Change the name of one of them and it should fix your problem.

score 1 · Answer 3 · answered Feb 16 '16 at 20:59

I got this error when I had code that explicitly setting route names using a RouteAttribute, when I was trying to set up a route that would take different arguments depending on whether it was called with HTTP GET or HTTP POST:

[HttpGet]
[Route("MyApiMethod", Name = "MyApiMethod")]
public MyApiMethod PropertyData(...)
{
    ...
}

// ERROR: Causes "System.ArgumentException: A route named 'DefaultRoute' is already in the route collection. Route names must be unique."
[HttpPost]
[Route("MyApiMethod", Name = "MyApiMethod")]
public MyApiMethod PropertyData(...)
{
    ...
}

This wasn't immediately obvious to me, but the problem turned out to be exactly what the error message says: I had two routes with the same Name value. Just changing those Name values to be unique (without needing top change the route itself or the method signatures) fixed the issue:

[HttpGet]
[Route("MyApiMethod", Name = "MyApiMethod-GET")]
public MyApiMethod PropertyData(...)
{
    ...
}

[HttpPost]
[Route("MyApiMethod", Name = "MyApiMethod-POST")]
public MyApiMethod PropertyData(...)
{
    ...
}

score 1 · Answer 4 · answered Aug 26 '18 at 17:43

1

Cleaning the solution/project didn't work for me. I ended up navigating to the bin directory and deleting all the files in the directory because it was an absolute mess and that resolved the problem for me.

answered Aug 26 '18 at 17:43

GrayDwarf

2,469
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score 0 · Answer 5 · answered Apr 29 '16 at 11:37

0

check In Global.asax

Two Time You have been Defined.

AreaRegistration.RegisterAllAreas();

Unload project and Reload Project.

answered Apr 29 '16 at 11:37

Pratik Panchal

71
1
3

score 0 · Answer 6 · answered Mar 03 '17 at 13:15

0

I had same issue. If you use IIS 8.X, you should check new features.

Your application pool Start Mode should be "AlwaysRunning" in Advanced Settings.
Your application PreLoad Enabled should be set to "True" in Advanced Settings.

Hope this helps.

answered Mar 03 '17 at 13:15

nevra

418
1
7
21

score 0 · Answer 7 · answered Oct 23 '17 at 11:25

0

just clean SOlution and Rebuild again !

it solves issue for me

answered Oct 23 '17 at 11:25

Amit N Thore

191
1
3

A route named 'DefaultRoute' is already in the route collection. Route names must be unique

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