This browser is no longer supported.
Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support.
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(105.60000000000001, 78%, 20%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EBM%3C/text%3E%3C/svg%3E)
root@ubuntu:/etc/systemd/system# /usr/bin/dotnet /var/www/MinAPI/WebApi.dll
You must install or update .NET to run this application.
App: /var/www/MinAPI/WebApi.dll
Architecture: x64
Framework: 'Microsoft.AspNetCore.App', version '5.0.0' (x64)
.NET location: /usr/lib/dotnet/
The following frameworks were found:
7.0.5 at [/usr/lib/dotnet/shared/Microsoft.AspNetCore.App]
Learn about framework resolution:
https://aka.ms/dotnet/app-launch-failed
To install missing framework, download:
https://aka.ms/dotnet-core-applaunch?framework=Microsoft.AspNetCore.App&framework_version=5.0.0&arch=x64&rid=ubuntu.23.04-x64
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(48, 84%, 14%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3ERO%3C/text%3E%3C/svg%3E)
thank you
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(51.2, 3%, 14%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3ELS%3C/text%3E%3C/svg%3E)
Has anyone managed to fix this? I'm getting the same error on Ubuntu 24.04. I'm using .NET 9 — it asked me to install version 8, but that didn’t work either
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(211.20000000000002, 61%, 30%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EBS%3C/text%3E%3C/svg%3E)
you need to install the obsolete .net 5.0 runtime:
https://dotnet.microsoft.com/en-us/download/dotnet/5.0
or get a .net 7 build of the app.
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(102.4, 63%, 19%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EAC%3C/text%3E%3C/svg%3E)
how to install the .NET package on Azure bash?
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(128, 8%, 22%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EA%3C/text%3E%3C/svg%3E)
Installing version 5.0 worked for me. Thank you.
This comment has been deleted due to a violation of our Code of Conduct. The comment was manually reported or identified through automated detection before action was taken. Please refer to our Code of Conduct for more information.
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(54.400000000000006, 93%, 15%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EBJ%3C/text%3E%3C/svg%3E)
If you are seeing this error in your Azure DevOps CI pipeline, you need to add the following task to your Yaml file, just before the build step:
- task: UseDotNet@2
displayName: 'Use .NET 5 sdk'
inputs:
packageType: sdk
version: '5.0.x'
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(313.6, 49%, 40%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3ECD%3C/text%3E%3C/svg%3E)
What if it's not in a Azure Devops CI pipeline. Then what?
Hi Byron Jones,
Just wanted to clarify something here: the error isnt happening in Azure DevOps pipeline. That log line root@ubuntu:/etc/systemd/system# /usr/bin/dotnet /var/www/MinAPI/WebApi.dll shows the app is being run directly on Ubuntu box, not on a hosted build agent. So the problem is runtime/framework mismatch on the target machine, not missing SDK on build agent.
The UseDotNet@2 task only affects the toolset inside CI job (downloads the requested SDK onto hosted agent), doesnt change what runtimes are installed on the Ubuntu server where app actually runs. Also .NET 5 has been out of support for a while so recommending it for new deployments is honestly kinda risky.
This YAML snippet might help someone who sees same message during CI, but doesnt really address the OPs runtime issue on Ubuntu in this thread.
What the error is telling you is basically. Your app was built for Microsoft.AspNetCore.App 5.0.0, but on this machine only 7.0.5 is installed. The .NET host will not jump from 5.0 to 7.0 automatically, so it just fails with the generic “You must install or update .NET to run this application” message.
So right now:
– The app targets net5.0 / AspNetCore 5.0.0.
– The server only has AspNetCore 7.0.5 installed.
– .NET 5 is already end-of-life and isn’t officially provided for newer Ubuntu releases anymore.
The best fix is not to fight the runtime, but to upgrade the app...
On your dev machine, open the project and change the TargetFramework in the csproj to net7.0 (or net8.0 if you can).
Update your ASP.NET Core and other NuGet packages to supported versions.
Deploy the new DLLs to the server and run the same command: /usr/bin/dotnet /var/www/MinAPI/WebApi.dll
Since the server already has Microsoft.AspNetCore.App 7.0.5, once your app targets net7.0 the host will find a matching framework and the error will simply disappear.
If, for some reason, you really can’t touch the code and must run this exact net5.0 dll on a modern Ubuntu, that’s where life gets ugly: .NET 5 is out of support and not officially available for newer Ubuntu releases, plus there are OpenSSL compatibility issues. At that point you’d need either an older, supported OS like Ubuntu 20.04 or a custom manual installation of the old runtime, which is not something you want in production.
You don’t think of this as .NET is broken :).. think of it as "the app’s required framework version doesn’t match what’s installed on the box". The durable solution is to move the app to a supported .NET version rather than chasing an obsolete runtime on a new distro.