aspnetcore: [Blazor] DOMException: Entry already exists

Describe the bug

When running a simple Blazor WASM app I am seeing errors in the console saying “DOMException: Entry already exists”.

For me, this only happens in Chrome.

To Reproduce

Run this app. https://drive.google.com/open?id=1MnWAzjHcMT60wbBlUhh_haIkTLM88vbo

Error details

Uncaught (in promise) DOMException: Entry already exists.

u | @ | blazor.webassembly.js:1
-- | -- | --
  | Promise.then (async) |   |  
  | s | @ | blazor.webassembly.js:1
  | a | @ | blazor.webassembly.js:1
  | Promise.then (async) |   |  
  | s | @ | blazor.webassembly.js:1
  | (anonymous) | @ | blazor.webassembly.js:1
  | r | @ | blazor.webassembly.js:1
  | e.addToCacheAsync | @ | blazor.webassembly.js:1
  | (anonymous) | @ | blazor.webassembly.js:1
  | (anonymous) | @ | blazor.webassembly.js:1
  | (anonymous) | @ | blazor.webassembly.js:1
  | a | @ | blazor.webassembly.js:1
  | Promise.then (async) |   |  
  | s | @ | blazor.webassembly.js:1
  | a | @ | blazor.webassembly.js:1
  | Promise.then (async) |   |  
  | s | @ | blazor.webassembly.js:1
  | (anonymous) | @ | blazor.webassembly.js:1
  | r | @ | blazor.webassembly.js:1
  | e.loadResourceWithCaching | @ | blazor.webassembly.js:1
  | e.loadResource | @ | blazor.webassembly.js:1
  | (anonymous) | @ | blazor.webassembly.js:1
  | e.loadResources | @ | blazor.webassembly.js:1
  | (anonymous) | @ | blazor.webassembly.js:1
  | callRuntimeCallbacks | @ | dotnet.3.2.0-preview3.20168.1.js:1
  | preRun | @ | dotnet.3.2.0-preview3.20168.1.js:1
  | run | @ | dotnet.3.2.0-preview3.20168.1.js:1
  | runCaller | @ | dotnet.3.2.0-preview3.20168.1.js:1
  | removeRunDependency | @ | dotnet.3.2.0-preview3.20168.1.js:1
  | receiveInstance | @ | dotnet.3.2.0-preview3.20168.1.js:1
  | (anonymous) | @ | blazor.webassembly.js:1
  | (anonymous) | @ | blazor.webassembly.js:1
  | (anonymous) | @ | blazor.webassembly.js:1
  | a | @ | blazor.webassembly.js:1
  | Promise.then (async) |   |  
  | s | @ | blazor.webassembly.js:1
  | a | @ | blazor.webassembly.js:1
  | Promise.then (async) |   |  
  | s | @ | blazor.webassembly.js:1
  | (anonymous) | @ | blazor.webassembly.js:1
  | r | @ | blazor.webassembly.js:1
  | p.instantiateWasm | @ | blazor.webassembly.js:1
  | createWasm | @ | dotnet.3.2.0-preview3.20168.1.js:1
  | (anonymous) | @ | dotnet.3.2.0-preview3.20168.1.js:1

Further technical details

  • ASP.NET Core version 3.1.2

  • The IDE (VS / VS Code/ VS4Mac) you’re running on, and it’s version Version 16.6.0 Preview 2.0

  • Include the output of dotnet --info

.NET Core SDK (reflecting any global.json):
 Version:   3.1.300-preview-015048
 Commit:    13f19b4682

Runtime Environment:
 OS Name:     Windows
 OS Version:  10.0.17763
 OS Platform: Windows
 RID:         win10-x64
 Base Path:   C:\Program Files\dotnet\sdk\3.1.300-preview-015048\

Host (useful for support):
  Version: 3.1.2
  Commit:  916b5cba26

.NET Core SDKs installed:
  2.1.505 [C:\Program Files\dotnet\sdk]
  3.1.101 [C:\Program Files\dotnet\sdk]
  3.1.200 [C:\Program Files\dotnet\sdk]
  3.1.300-preview-015048 [C:\Program Files\dotnet\sdk]

.NET Core runtimes installed:
  Microsoft.AspNetCore.All 2.1.9 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.All 2.1.16 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
  Microsoft.AspNetCore.App 2.1.9 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 2.1.16 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 3.0.0-preview8.19405.7 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 3.1.1 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 3.1.2 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 2.1.9 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 2.1.16 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 3.0.0-preview8-28405-07 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 3.1.1 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.NETCore.App 3.1.2 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.WindowsDesktop.App 3.0.0-preview8-28405-07 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 3.1.1 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
  Microsoft.WindowsDesktop.App 3.1.2 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

About this issue

  • Original URL
  • State: closed
  • Created 4 years ago
  • Reactions: 3
  • Comments: 27 (5 by maintainers)

Commits related to this issue

Most upvoted comments

I got those errors also in Edge (Chromium).

@pranavkm I’ve tested a few scenarios. It only seems to be a problem (for me) when VS is responsible for launching the browser.

When VS launches Chrome I see the problem. If I open a new tab in the same browser and go to the URL I see the problem. If I open an incognito window and go to the URL, no errors. If I open a new instance of Chrome (not incognito) no errors (whether signed in or as Guest).

I hope that helps.

I experience this issue as well but @mrpmorris is correct, only in the browser window that VS2019 16.6 opens. If I open the URL in another browser instance then no error.

same issue here ,got 113 Uncaught (in promise) DOMException: Entry already exists. when I upgrade package to 3.2 and launch blazor template project

I’m experiencing the same issue using the 3.2.0 WebAssembly NuGet packages.