Web API in MVC Project isn't hitting breakpoints ("symbols not loaded")

Question

I have an ASP.NET MVC project, with an ASP.NET web api defined as an area in this project. So the structure is the following:

MVC Web
   Controllers
   Views
   Areas
     API (web API)
       Controllers

The app works as expected. However, I am having an issue with debugging. I can put a debugger in the MVC controller, and it works as expected. I cannot put a breakpoint in the web API controller, as I get "the breakpoint will not currently be hit. No symbols have been loaded for this document." I've been in the throes of it for some time, so it's probably a simple fix but I cannot figure it out. Any ideas why I'm getting this problem with web API controllers, when I can debug an MVC controller?

I often find this when my assemblies I am trying to use are not compiling as I expected. Make sure you are compiling all your classlibs and doing rebuild all. HTH's (BTW, I can hit my webapi controller debug with no issue so it's not fundamentally a problem I think) — Peter Kellner, Jan 01 '13 at 06:55
If you're using IIS Express, try shutting it down and letting VS fire it back up after you "Rebuild" your solution. — anAgent, Jan 02 '13 at 23:30
For me, I had this problem when the WebApi project was not set as the startup project for the solution. Making my project the startup one solved the problem. — NickBeaugié, Oct 14 '13 at 16:39

score 27 · Accepted Answer · edited Feb 22 '16 at 21:06

27

Until you find a permanent solution you can use the method System.Diagnostics.Debugger.Break() to force a break to occur on that line - just like a breakpoint:

public ActionResult IndexCheckInOut(string providerKey, DateTime? date = null)
{
    System.Diagnostics.Debugger.Break();   
    return View("Index");
}

Here are some links to articles that might help you find a more permanent solution:

The breakpoint will not currently be hit

Stepping into ASP.NET MVC source code with Visual Studio debugger

edited Feb 22 '16 at 21:06

Luis Perez

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answered Jan 01 '13 at 13:22

Sampath

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The last link was the solution. The solution for me was to disable "enable just my code". – Brian Mains Jan 02 '13 at 00:51
1

The last link worked for me as well, but I also had to clean and rebuild my project. – Dowlers Jul 05 '17 at 21:44
@Dowlers same for me. Just needed to clean and rebuild. – Joao Soares Mar 03 '22 at 00:53

score 5 · Answer 2 · edited Mar 04 '19 at 10:59

Possible solution: I had forgotten that I was previously doing some remote debugging and had set debug symbols to be loaded from a UNC path instead of the Microsoft Symbol Servers.

To fix this head to: Tools -> Options -> Debugging -> Symbols -> Make sure 'Microsoft Symbol Servers' is checked.

I also found this issue from creating a new Solution Configuration and not basing it on any existing configuration, such as the DEBUG configuration. That caused Debug Info to be set to none.

To fix this: Right-click your project -> Properties -> Build -> Make sure your faulty Solution Configuration is set -> click Advanced -> change Debug Info to full.

score 5 · Answer 3 · answered Oct 04 '16 at 11:41

5

For me it worked out to just stop IIS and restart Visual Studio. Definitely worth a try before further investigation.

answered Oct 04 '16 at 11:41

FrKunze

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live-love · Answer 4 · 2019-02-25T19:22:27.237

3

Open:

Tools - Options - Debugging - General

Select:

Enable .NET Framework source stepping
Enable source server support (all options selected)

Open:

Tools - Options - Symbol

Select Microsoft Symbol Servers

Click Load All Symbols

Rebuild the project.

Select:

Clean

Rebuild

Rebuild solution and try again.

edited Feb 25 '19 at 19:22

answered Feb 25 '19 at 18:00

live-love

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score 1 · Answer 5 · answered Sep 11 '19 at 15:23

Just had this issue myself and was tearing my hair out for about an hour until I realised Visual Studio had mysteriously switched to run the project in 'Release' mode. Switching back to 'Debug' mode and rebuilding sorted me out.

Probably a very niche answer to this problem, but hopefully this helps somebody.

score 0 · Answer 6 · answered Jan 23 '19 at 14:47

0

This solved my problem:

Close\Exit from all instances of IIS Express in the system tray (beside the Windows clock).
Delete bin and obj folders in your project directory
Restart Visual Studio
Run it again

answered Jan 23 '19 at 14:47

Leniel Maccaferri

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score 0 · Answer 7 · answered Sep 11 '19 at 19:03

0

I had the same issue but mine was related to the addition of a config Transform. Go to Build > Configuration Manager under Active Solution Configuration make sure you have Debug selected.

answered Sep 11 '19 at 19:03

AtLeastTheresToast

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score 0 · Answer 8 · answered Apr 08 '21 at 12:08

My problem was the following

I had created a virtual directory in my IIS and use that name in my start URL link like http://WebAPI/swagger/ui/index (My symbols where not loaded with all the above steps)

Use IIS Express
Deleted the website from IIS Manager called WebAPI
Start URL I changed back to is http://localhost:59788/swagger/ui/index (Default port from visual studio)

Now all my symbols are loaded.

score 0 · Answer 9 · answered Sep 23 '21 at 10:56

0

if your debug worked and suddenly stopped working, the most common reason in my experience is problem in the IIS.

check that project->properties -> project URL is correct,
use IISReset to reset IIS

answered Sep 23 '21 at 10:56

Citizen-Dror

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score 0 · Answer 10 · edited Mar 09 '23 at 04:34

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app.MapControllers() was missing from program.cs

I only stumbled across this on a medium article, fortunately!!

(I’m using .net 7.0)

It was very odd because my first get-all sales were being returned, that only returned a simple entity type though!

Now I can clearly see 500 errors. For example, the AdventureWorks 2017 SalesOrderDetail table requires two integers for its primary key!

edited Mar 09 '23 at 04:34

Mahyar Mottaghi Zadeh

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answered Mar 03 '23 at 07:05

Paul Kersey

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Web API in MVC Project isn't hitting breakpoints ("symbols not loaded")

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