.Net 6 Upgrade

Shashi 6

Hi Team,

We are updating the .Net Core 3.1 framework to .Net 6 then we are getting this error.

System.TypeInitializationException: 'The type initializer for 'Microsoft.EntityFrameworkCore.EnumerableMethods' threw an exception.'

InvalidOperationException: Sequence contains more than one matching element

We have used a few libraries projects and its created with .Net Standard library 2.0

Jiachen Li-MSFT 26,671 Reputation points Microsoft Vendor

2021-11-11T06:40:15.79+00:00

Hi @Shashi ,
Does your program run successfully in .Net Core3.1?
And have you tried running your program on .Net 5?
Waiting for your update.
Shashi 6 Reputation points

2021-11-11T08:45:49.387+00:00

Does your program run successfully in .Net Core3.1? Yes, its works properly.

And have you tried running your program on .Net 5? -- No, I am upgrading from .Net Core 3.1 to .Net 6.
Jiachen Li-MSFT 26,671 Reputation points Microsoft Vendor

2021-11-11T09:38:49.683+00:00

Hi @Shashi ,
What's your Visual Studio version? .Net 6 is recommended to be used on Visual Studio 2022.
Since .Net 6 and Visual Studio 2022 are all newly released, you can consider testing it on .Net5 which is a more stable version.
Besides, if your project works well on .net5, you can post your question on GitHub issue tracker for more help about .NET6.

2 answers

Max Calvin 21 Reputation points

2021-11-16T10:04:29.887+00:00

Hi @Shashi - I've had this issue when I tried to move to .net 6, turns out it just needed the EF nuget package updated to the latest version. Something about .net 6 and the older EF versions wasn't playing nicely.

Not sure if you have the same problem but it's worth a try if you haven't upgraded it yet.

Good luck!
Max
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4 people found this answer helpful.
Dany 6 Reputation points

2021-11-22T05:52:16.433+00:00

Hey @Max Calvin Thanks mate, it worked for me.

Jiachen Li-MSFT 26,671 Reputation points Microsoft Vendor

2021-11-23T09:47:10.163+00:00

Hi @Shashi ,
I am glad to see that your problem has been solved.
If this answer is helpful, please click "Accept Answer" so that others can quickly locate the problem and find a solution.

Luis Marano 1 Reputation point

2022-05-10T17:28:42.717+00:00

Hi, @Max Calvin , your answer solved my problem, Thanks.

Lavanya Nooka 1 Reputation point

2022-05-23T06:57:00.453+00:00

Hi @Max Calvin which version of EF core did you upgrade the .net 6 code to. I am having the same issue.
Thank you

Boris Guzner 0 Reputation points

2023-03-12T03:40:04.44+00:00

@Max Calvin 's answer helped me. I had the same runtime error after upgrading my project from .net core 3.1 to .net 6. After upgrading EF nuget packages from 3.1.13 to 6.0.14 and no other database or code changes, the project is running without errors.
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Shan Nagarajan 0

Need to update DB Project (dacpack) entity framework version, after updating below changes it is working.

    <PackageReference Include="Microsoft.Azure.Services.AppAuthentication" Version="1.6.2" />
    <PackageReference Include="Microsoft.EntityFrameworkCore" Version="6.0.10" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="6.0.10">
    <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="6.0.10" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="6.0.10">