HotReload In BlazorWebAssembly Dont Work Correctly

[shabanelmogy-os]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

i use blazor webassembly standalone in .net 9 hotreload not work and this make development very difficult and waste time
please solve this problem because most of blazor prgrammer might migrate to another framework
if anyone has production app it will be big problem

Expected Behavior

No response

Steps To Reproduce

No response

Exceptions (if any)

No response

.NET Version

.net 9

Anything else?

No response

[javiercn]

@shabanelmogy-os thanks for contacting us.

Can you provide a concrete description of what exactly is not working? otherwise is impossible for us to take any action.

[danroth27]

@shabanelmogy-os It would help if you could include the following specific details:

• What operating system you are using?
• What tool are you using to perform the hot reload? VS, VSCode, or dotnet watch
• What sort of change are you trying to hot reload? What is the original code and what change did you make?
• Are there any errors in the hot reload output window?

@phil-allen-msft FYI

[ghostinside]

+1, just updated to VS.NET 17.12.4, it seems the .net 9 was added with an update, but the web assembly project hot reload stopped working. rebuild (ctrl+R tries to open the browser all the time), the console shows that the hot reload was applied, and the application crashed in the browser.

web assemble, not hosted project

Update: rollback to VS.Net 17.11.5 fixed all issues

[rabberbock]

I just upgraded one of our projects to .NET 9 and the blazor wasm hot reload just does not work well anymore. I use dotnet watch from cli on a Mac.

Here are some error logs from my latest run. I was not doing anything fancy, just changing css classes. Also dotnet watch outputs 100's of files in the log for every change, maybe that it part of the issue.

Reddit thread as well.

For now I am going to stick with the dotnet watch --no-hot-reload option.

Let me know if you want anything specific and I can try to pull it together. Thanks!

[danroth27]

@rabberbock Thanks for sharing this additional information.

@lewing Can you take a look and see if this is something we need to investigate on the runtime side?

[ghostinside]

my case the project is still .net 8, dot net watch, when you rebuild the first time, it works till the first hot reload, during the hot reload I see that the changed file was removed and added (cli messages in the console), and the second time it starts warning that we have unknown component on the page & need to add a namespace, the hot reload in console still a success, browser app crashed

[lewing]

cc @tmat

[tmat]

@rabberbock

ctrl+R tries to open the browser all the time

This is tracked by dotnet/sdk#46175

[tmat]

@rabberbock
Would you mind setting env variable Microsoft_CodeAnalysis_EditAndContinue_LogDir=%temp%\HotReloadLog before starting dotnet watch --verbose and sharing the verbose output and content of the log directory?

Note, the logs will contain pieces of your source code. You can use VS Feedback if you prefer not sharing the code publicly.

[ghostinside]

this is also became "as usual"

console:

dotnet watch ⌚ File changed: .\Features\Shipments\ShipmentDetails.razor. dotnet watch 🔥 Hot reload of changes succeeded. dotnet watch ⌚ File changed: .\Features\Shipments\ShipmentDetails.razor. dotnet watch 🔥 Hot reload of changes succeeded. dotnet watch ⌚ File changed: .\Features\Shipments\ShipmentDetails.razor. dotnet watch ⌚ No hot reload changes to apply.

browser:

crit: Microsoft.AspNetCore.Components.WebAssembly.Rendering.WebAssemblyRenderer[100] Unhandled exception rendering component: Could not load file or assembly 'essContactListAsync>b__8_0, Version=8.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60' or one of its dependencies. System.IO.FileNotFoundException: Could not load file or assembly 'essContactListAsync>b__8_0, Version=8.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60' or one of its dependencies. File name: 'essContactListAsync>b__8_0, Version=8.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60' at Microsoft.AspNetCore.Components.ComponentBase.<.ctor>b__6_0(RenderTreeBuilder builder) at Microsoft.AspNetCore.Components.Rendering.ComponentState.RenderIntoBatch(RenderBatchBuilder batchBuilder, RenderFragment renderFragment, Exception& renderFragmentException)

this does not exist in real live - essContactListAsync

refresh does not help, just rebuild & refresh

.NET SDK:
Version: 8.0.405
Commit: fb1830d421
Workload version: 8.0.400-manifests.87fdb0b5
MSBuild version: 17.11.9+a69bbaaf5

Runtime Environment:
OS Name: Windows
OS Version: 10.0.22631
OS Platform: Windows
RID: win-x64
Base Path: C:\Program Files\dotnet\sdk\8.0.405\

.NET workloads installed:
Configured to use loose manifests when installing new manifests.
[aspire]
Installation Source: VS 17.11.35327.3
Manifest Version: 8.1.0/8.0.100
Manifest Path: C:\Program Files\dotnet\sdk-manifests\8.0.100\microsoft.net.sdk.aspire\8.1.0\WorkloadManifest.json
Install Type: Msi

[maui-windows]
Installation Source: VS 17.11.35327.3
Manifest Version: 8.0.82/8.0.100
Manifest Path: C:\Program Files\dotnet\sdk-manifests\8.0.100\microsoft.net.sdk.maui\8.0.82\WorkloadManifest.json
Install Type: Msi

[maccatalyst]
Installation Source: VS 17.11.35327.3
Manifest Version: 18.0.8303/8.0.100
Manifest Path: C:\Program Files\dotnet\sdk-manifests\8.0.100\microsoft.net.sdk.maccatalyst\18.0.8303\WorkloadManifest.json
Install Type: Msi

[ios]
Installation Source: VS 17.11.35327.3
Manifest Version: 18.0.8303/8.0.100
Manifest Path: C:\Program Files\dotnet\sdk-manifests\8.0.100\microsoft.net.sdk.ios\18.0.8303\WorkloadManifest.json
Install Type: Msi

[wasm-tools-net6]
Installation Source: VS 17.11.35327.3
Manifest Version: 8.0.12/8.0.100
Manifest Path: C:\Program Files\dotnet\sdk-manifests\8.0.100\microsoft.net.workload.mono.toolchain.net6\8.0.12\WorkloadManifest.json
Install Type: Msi

[android]
Installation Source: VS 17.11.35327.3
Manifest Version: 34.0.113/8.0.100
Manifest Path: C:\Program Files\dotnet\sdk-manifests\8.0.100\microsoft.net.sdk.android\34.0.113\WorkloadManifest.json
Install Type: Msi

Host:
Version: 8.0.12
Architecture: x64
Commit: 89ef51c5d8

.NET SDKs installed:
3.1.426 [C:\Program Files\dotnet\sdk]
5.0.203 [C:\Program Files\dotnet\sdk]
5.0.214 [C:\Program Files\dotnet\sdk]
5.0.303 [C:\Program Files\dotnet\sdk]
5.0.408 [C:\Program Files\dotnet\sdk]
6.0.203 [C:\Program Files\dotnet\sdk]
6.0.321 [C:\Program Files\dotnet\sdk]
8.0.112 [C:\Program Files\dotnet\sdk]
8.0.206 [C:\Program Files\dotnet\sdk]
8.0.403 [C:\Program Files\dotnet\sdk]
8.0.405 [C:\Program Files\dotnet\sdk]

.NET runtimes installed:
Microsoft.AspNetCore.All 2.1.30 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
Microsoft.AspNetCore.App 2.1.30 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 3.1.15 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 3.1.18 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 3.1.32 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 5.0.5 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 5.0.6 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 5.0.9 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 5.0.13 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 5.0.17 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 6.0.5 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 6.0.26 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 8.0.6 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 8.0.10 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 8.0.12 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.NETCore.App 2.1.30 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 3.1.15 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 3.1.18 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 3.1.32 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 5.0.5 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 5.0.6 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 5.0.9 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 5.0.13 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 5.0.17 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 6.0.5 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 6.0.15 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 6.0.26 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 8.0.6 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 8.0.10 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 8.0.12 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.WindowsDesktop.App 3.1.15 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 3.1.18 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 3.1.32 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 5.0.6 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 5.0.9 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 5.0.17 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 6.0.5 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 6.0.15 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 6.0.26 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 8.0.6 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 8.0.10 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 8.0.12 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

Other architectures found:
arm64 [C:\Program Files\dotnet]
registered at [HKLM\SOFTWARE\dotnet\Setup\InstalledVersions\arm64\InstallLocation]
x86 [C:\Program Files (x86)\dotnet]
registered at [HKLM\SOFTWARE\dotnet\Setup\InstalledVersions\x86\InstallLocation]

Environment variables:
Not set

global.json file:
Not found

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