"CLR initialization error in SQL Server query operation 0x80004005"

Question

Steps to reproduce:

1. Use SQL Server Management Studio to connect to the target SQL Server instance.
2. Perform a specific query operation in the Query Editor, involving certain tables.（Only a few tables have this phenomenon）
3. Error "Unable to initialize common language runtime (CLR) v4.0.30319 using HRESULT 0x80004005. You need to restart SQL Server to use CLR integration features. "

Environment Information:

1. SQL Server edition:SQL Server 2019
2. Operating system: Windows Server 2019
3. CLR Configuration: true

Workaround tried：

1. Restarting SQLServer has no effect

Answer 1

Hi @Zhou, Qijun

Try running the following in the database that is giving you this problem:

select * from sys.assemblies        --This is important to check.
select * from sys.dm_clr_properties --This is important to check.

Also, try reinstalling the .net framework or try repairing it using this tool:
http://www.microsoft.com/en-us/download/details.aspx?id=30135

Best regards,

Cosmog Hong

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Answer 2

What does "SELECT @@version" return? If the result does not say RTM-CU21, make sure you apply the most recent Cumulative Update.

Also try the repair suggested by Cosmog.

If none of these actions helps, I recommend that you open a support case with Microsoft. As this is something which is specific to your site, it is very difficult for us to assist. And furthermore, as this smells like a bug, opening a case is the only way you can get a fix.