Templating: Dotnet new fails: Object reference not set to an instance of an object

[AllanRegush]

Steps to reproduce

dotnet new console and dotnet new

Expected behavior

Creates a new console app / lists help for dotnet new

Actual Behavior

Getting ready...
Object reference not set to an instance of an object.
   at Microsoft.TemplateEngine.Edge.Settings.SettingsLoader.Save(TemplateCache cacheToSave)
   at Microsoft.TemplateEngine.Edge.Settings.SettingsLoader.Save()
   at Microsoft.TemplateEngine.Cli.Installer.InstallPackages(IEnumerable`1 installationRequests, IList`1 nuGetSources, Boolean debugAllowDevInstall)
   at Microsoft.TemplateEngine.Cli.Installer.InstallPackages(IEnumerable`1 installationRequests)
   at Microsoft.DotNet.Tools.New.NewCommandShim.FirstRun(IEngineEnvironmentSettings environmentSettings, IInstaller installer)
   at Microsoft.TemplateEngine.Cli.New3Command.ConfigureEnvironment()
   at Microsoft.TemplateEngine.Cli.New3Command.Initialize()
   at Microsoft.TemplateEngine.Cli.New3Command.ExecuteAsync()
   at Microsoft.TemplateEngine.Cli.CommandParsing.NewCommandInputCli.<>c__DisplayClass19_0.<<OnExecute>b__0>d.MoveNext()

Environment Data

dotnet --info

```bash
.NET Core SDK (reflecting any global.json):
Version: 3.1.100
Commit: cd82f021f4

Runtime Environment:
OS Name: opensuse-tumbleweed
OS Version: 20191204
OS Platform: Linux
RID: linux-x64
Base Path: /usr/share/dotnet/sdk/3.1.100/

Host (useful for support):
Version: 3.1.0
Commit: 157910edee

.NET Core SDKs installed:
3.1.100 [/usr/share/dotnet/sdk]

.NET Core runtimes installed:
Microsoft.AspNetCore.App 3.1.0 [/usr/share/dotnet/shared/Microsoft.AspNetCore.App]
Microsoft.NETCore.App 3.1.0 [/usr/share/dotnet/shared/Microsoft.NETCore.App]

To install additional .NET Core runtimes or SDKs:
https://aka.ms/dotnet-download

Tried Fixes in [Dotnet new fails: Object reference not set to an instance of an object #657](https://github.com/dotnet/templating/issues/657)

ie. 
```bash
dotnet new --debug:reinit
rm -rf ~/.templateengine

Did not have this problem with dotnet sdk 2.0.

[AllanRegush]

Update: I installed dotnet core 3.1 via snap - works fine. Could be something missing in the official opensuse package or due to tumbleweed having a different libicu package (libicu-suse65_1).

[mdx0111]

I'm having exact same problem on Fedora 31.
Running dotnet new throws the following:

Getting ready... Object reference not set to an instance of an object. at Microsoft.TemplateEngine.Edge.Settings.SettingsLoader.Save(TemplateCache cacheToSave) at Microsoft.TemplateEngine.Edge.Settings.SettingsLoader.Save() at Microsoft.TemplateEngine.Cli.Installer.InstallPackages(IEnumerable1 installationRequests, IList1 nuGetSources, Boolean debugAllowDevInstall) at Microsoft.TemplateEngine.Cli.Installer.InstallPackages(IEnumerable1 installationRequests)
at Microsoft.DotNet.Tools.New.NewCommandShim.FirstRun(IEngineEnvironmentSettings environmentSettings, IInstaller installer)
at Microsoft.TemplateEngine.Cli.New3Command.ConfigureEnvironment()
at Microsoft.TemplateEngine.Cli.New3Command.Initialize()
at Microsoft.TemplateEngine.Cli.New3Command.ExecuteAsync()
at Microsoft.TemplateEngine.Cli.CommandParsing.NewCommandInputCli.<>c__DisplayClass19_0.<b__0>d.MoveNext()`

This is the output of my dotnet --info:

`.NET Core SDK (reflecting any global.json):
Version: 3.1.100
Commit: cd82f021f4

Runtime Environment:
OS Name: fedora
OS Version: 31
OS Platform: Linux
RID: fedora.31-x64
Base Path: /usr/share/dotnet/sdk/3.1.100/

Host (useful for support):
Version: 3.1.0
Commit: 157910edee

.NET Core SDKs installed:
3.1.100 [/usr/share/dotnet/sdk]

.NET Core runtimes installed:
Microsoft.AspNetCore.App 3.1.0 [/usr/share/dotnet/shared/Microsoft.AspNetCore.App]
Microsoft.NETCore.App 3.1.0 [/usr/share/dotnet/shared/Microsoft.NETCore.App]

To install additional .NET Core runtimes or SDKs:
https://aka.ms/dotnet-download
`
Any help would be appreciated.

Thanks.

[mdx0111]

I fixed it by wiping the "/usr/share/dotnet/templates" and "~/.templateengine" folders. Then reinstalling dotnet core 3.1 and then running dotnet new --debug:reinit.

Everything works fine now.

[limup]

I fixed it by wiping the "/usr/share/dotnet/templates" and "~/.templateengine" folders. Then reinstalling dotnet core 3.1 and then running dotnet new --debug:reinit.

Everything works fine now.

Thanks!

[GeorgeGomez]

I fixed it by wiping the "/usr/share/dotnet/templates" and "~/.templateengine" folders. Then reinstalling dotnet core 3.1 and then running dotnet new --debug:reinit.

Everything works fine now.

sweet!

[tanero]

I have recieved same error today while installing dotnet 3.1 on centos7. First try was, i've removed all versions by calling yum remove dotnet* and install dotnet 3.1 but no success. (same error.)

Second, uninstalled dotnet 3.1 and deleted remaining files with folder, /usr/share/dotnet. In this time, server were clean and installed dotnet 3.1 again.

Voila, everything working as usual.

[rescobarm]

Tenía el mismo problema con net5.0. Borré "/usr/share/dotnet/templates" como dice JorgeGomez y listo.
Pero ahora me sale el siguiente error: The framework 'Microsoft.AspNetCore.App', version '5.0.0' was not found.