Rider unable to publish solutions when using the slnx solution format
When I try and publish a soluton from Rider, I get the following error when using the new slnx solution format
The element <Solution> is unrecognized, or not supported in this context.
Does anyone else have this issue.
If you have sorted it, do you know how you did it?
I am using version 2024.3.3 (243.22562.250)
Any help would be greatly appreciated
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The project can be published via the dotnet command line, just not using Rider
Hello Phil,
I suppose you encountered a known issue:
slnxsupport in thedotnetCLI #40913 (fixed in the upcoming .net 9 release 9.0.200)Please watch it for further updates.
Have a nice day!
Hello,
Now it is possible to publish using Visual Srtudio 2026… but not with Rider: all the external references (nuget packages) are missing!
Hello Patrick,
Would you mind elaborating on the issue you observe? Are there any errors? Does Rider fail to restore nuget packages? What is the value for the Settings | Build, Execution, Deployment | NuGet | Restore | PackageReference Restore Engine setting do you have set?
Hello Dmitry,
No error when compiling or executing the application. Also no error when restoring nuget packages.
Settings | Build, Execution, Deployment | NuGet | Restore | PackageReference Restore Engine setting is set to automatic.
Here is the projects that are in my solution:
Here is the publish folder when publishing using the .slnx solution file (it's all):
Here is part of the publish folder when publishing using the .sln solution file:
Here is the build output when publishing using the .slnx solution file:
Here is the build output when publising using the .sln solution file:
Hello Patrick,
Thank you for the details shared. Unfortunately, I wasn't yet able to reproduce the issue. Would you mind sharing IDE logs as described below, so that we can take a closer look at the issue? Please do the following (see SUPPORT-A-275 How to collect Rider logs with Traces for details):
Additional note: Is it by chance possible to share a repro project with us? Did you try reproducing the issue with a newly created project?
Thank you in advance and have a great day!
Hello Dmitry,
For the upload:
Upload id: 2025_12_01_9MhfYw1JBSi51Q8zaWnfia (file: 54400.FIVB - WebService - C#.msbuild-task.zip)
I don't have tested with another solution.
Have a nice day.
Hello Patrick,
I see you attached a single file. Unfortunately, this isn't enough. Would you mind sharing the whole logs bundle as described below?
D:\FIVB\VisV2\Applications\WebService\Published\)Regards, Dmitry.
Hello Dmitri,
Here are the 2 logs: the first after publishing the `slnx` solution and the second after `sln`.
I hope you have all the necessary information.
Have a nice day.
Upload id: 2025_12_02_FASKazMbtCzRmoykwnfx8Y (files: Trace-1-after-slnx.zip, Trace-2-after-sln.zip)
Hello Patrick,
I see you publish different projects when open .slnx and then .sln solution. When you open .slnx, you publish the Fivb.Vis.Core.Server.csproj project. MSBuild args are:
Then you open .sln and publish another project: WebService.csproj. MSBuild args are:
Meantime, I found the potential cause of the confusion you encountered. I registered this issue: RIDER-134814 Configuration created under sln changes after opening .slnx
As a solution, upon opening the .slnx, go to Run | Edit Configurations → then ensure the proper project is selected in the Project field. I suppose you expect the
WebServiceproject to be published by that configuration, but it isFivb.Vis.Core.Serverthere.Hope that helps!
Hello Dmitry,
Thank you for your answer, as that was the problem.
You are welcome. I am glad to help. Should you have any questions or experience any difficulties in the future, do not hesitate to contact support.